Magnetoresistive effect element and magnetic memory

ABSTRACT

It is made possible to provide a highly reliable magnetoresistive effect element and a magnetic memory that operate with low power consumption and current writing and without element destruction. The magnetoresistive effect element includes a first magnetization pinned layer comprising at least one magnetic layer and in which a magnetization direction is pinned, a magnetization free layer in which a magnetization direction is changeable, a tunnel barrier layer provided between the first magnetization pinned layer and the magnetization free layer, a non-magnetic metal layer provided on a first region in an opposite surface of the magnetization free layer from the tunnel barrier layer, a dielectric layer provided on a second region other than the first region in the opposite surface of the magnetization free layer from the tunnel barrier layer; and a second magnetization pinned layer provided to cover opposite surfaces of the non-magnetic metal layer and the dielectric layer from the magnetization free layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromprior Japanese Patent Application No. 2005-197877 filed on Jul. 6, 2005in Japan, the entire contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a magnetoresistive effect element and amagnetic memory.

2. Related Art

Magnetoresistive effect elements using magnetic material films are usedin, for example, magnetic heads and magnetic sensors. In addition, it isproposed to use the magnetoresistive effect elements in solid stateMRAMs (Magnetic Random Access Memories).

As a magnetoresistive effect transistor element which has a sandwichstructure film formed by inserting a single layer of a dielectricbetween two ferromagnetic layers, which lets a current flowperpendicularly to the film surface, and utilizes a tunnel current, theso-called “ferromagnetic TMR (Tunneling Magneto-Resistance effect)element” is proposed. Since it has become possible to obtain amagnetoresistance change rate of 20% or more in the ferromagnetictunneling magneto-resistance effect element, technical development forcommercial application of the element to the MRAM is being conductedvigorously.

This TMR element can be implemented by forming a thin Al (aluminum)layer having a thickness in the range of 0.6 nm to 2.0 nm on aferromagnetic layer, exposing a surface of the Al layer to oxygen glowdischarge or oxygen gas, and thereby forming a tunnel barrier layer.

A ferromagnetic single tunnel junction having a structure obtained byproviding one of the ferromagnetic layers having the tunnel barrierlayer of a ferromagnetic single tunnel junction between with anantiferromagnetic layer is proposed. Furthermore, a ferromagnetic tunneljunction having magnetic particles scattered in a dielectric, and aferromagnetic double tunnel junction having a continuous film as each ofthe ferromagnetic layers.

These magnetoresistive effect elements also have a possibility of beingapplied to the MRAMs because it has become possible to obtain amagnetoresistance change rate in the range of 20% to 50% and thedecrease of the magnetoresistance change rate can also be suppressed byraising the voltage value applied to the TMR element to obtain a desiredoutput voltage value. If a TMR element is used as a memory element of anMRAM, one of ferromagnetic layers having a tunnel barrier layer betweenis used as a magnetization pinned layer and the other of theferromagnetic layers is used as a magnetic recording layer. The memoryelement using the ferromagnetic single tunnel junction or theferromagnetic double tunnel junction is non-volatile, and has apotential that a write and read time is 10 nanoseconds or less and thenumber of times of rewriting is also 10¹⁵ or more. Especially in thememory element using the ferromagnetic double tunnel junction, thedecrease of the magnetoresistance change rate can be suppressed even ifthe voltage value applied to the TMR element is raised, as describedabove. Therefore, a large output voltage is obtained, andcharacteristics that are favorable for the memory element are obtained.

As regards the cell size of the memory, there is a problem that the sizecannot be made smaller than a semiconductor DRAM (Dynamic Random AccessMemory) or less in the case where an architecture in which a memory cellis formed of one transistor and one TMR element.

In order to solve this problem, a diode type architecture including aseries connection composed of a TMR element and a diode between a bitline and a word line and a simple matrix type architecture obtained byarranging cells each having a TMR element between a bit line and a wordline are proposed.

In either case, inversion is conducted using a current magnetic fieldbased on a current pulse when writing to the magnetic recording layer isexecuted, resulting in high power consumption. When the capacity isincreased, there is a limit in allowable current density for wiring andconsequently a large capacity cannot be obtained. Unless the absolutevalue of the current is 1 mA or less, or it is 0.2 mA or less forsubstitution for DRAMs, the area of the driver increases. As comparedwith other non-volatile solid-state memories, such as ferroelectricrandom access memories using ferroelectric capacitors or flash memories,there is a problem that the chip becomes large and competitive power islost.

In order to solve the above-described problem, a solid-state magneticmemory having a thin film formed of a high permeability magneticmaterial around writing wiring is proposed. According to these magneticmemories, a high permeability magnetic film is provided around wiring,and consequently a current value required to write information into themagnetic recording layer can be reduced efficiently.

Even if they are used, however, it is very difficult to cause the writecurrent value to become 1 mA or less.

In order to solve these problems, a write method using a spin injectionmethod is proposed (see, for example, U.S. Pat. No. 6,256,223). Thisspin injection method utilizes inversion of magnetization of themagnetic recording layer obtained by injecting a spin-polarized currentinto the magnetic recording layer of the memory element.

In the case where the spin injection method is applied to the TMRelement, there is a problem of element destruction such as breakdown ofa tunnel insulation film and there is a problem in element reliability.

Even if writing is conducted using the spin injection method, therefore,it is necessary to provide a new magnetoresistive effect element, andmaterial, structure and architecture of a magnetic memory capable ofdecreasing the current density at the time of writing to the extent thatelement destruction is not caused.

As described heretofore, a new highly reliable magnetoresistive effectelement, and material, structure and architecture of a magnetic memorywhich make possible operation with low power consumption and low currentwriting and without element destruction are needed.

SUMMARY OF THE INVENTION

The present invention has been achieved on the basis of recognition ofsuch problems. An object of the present invention is to provide a highlyreliable magnetoresistive effect element that operates with low powerconsumption and low current writing, and a magnetic memory using such amagnetoresistive effect element.

A magnetoresistive effect element according to a first aspect of thepresent invention includes: a first magnetization pinned layer whichincludes at least one magnetic layer and in which a magnetizationdirection is pinned; a magnetization free layer in which a magnetizationdirection is changeable; a tunnel barrier layer provided between thefirst magnetization pinned layer and the magnetization free layer; anon-magnetic metal layer provided on a first region in an oppositesurface of the magnetization free layer from the tunnel barrier layer; adielectric layer provided on a second region other than the first regionin the opposite surface of the magnetization free layer from the tunnelbarrier layer; and a second magnetization pinned layer which includes atleast one magnetic layer and in which a magnetization direction ispinned, the second magnetization pinned layer being provided so as tocover opposite surfaces respectively of the non-magnetic metal layer andthe dielectric layer from the magnetization free layer.

An interface between the dielectric layer and the second magnetizationpinned layer and an interface between the non-magnetic metal layer andthe second magnetization pinned layer can be substantially coplanar.

An interface between the dielectric layer and the second magnetizationpinned layer can be located farther from an interface between the tunnelbarrier layer and the magnetization free layer than an interface betweenthe non-magnetic metal layer and the second magnetization pinned layer.

The second magnetization pinned layer can have a three-layer structurein which a first magnetic layer, a first non-magnetic layer, and asecond magnetic layer are stacked in order from a side of thenon-magnetic metal layer, or a five-layer structure in which a firstmagnetic layer, a first non-magnetic layer, a second magnetic layer, asecond non-magnetic layer, and a third magnetic layer are stacked inorder from the side of the non-magnetic metal layer, and an interfacebetween the dielectric layer and the second magnetization pinned layercan exist in the first magnetic layer.

A magnetoresistive effect element according to a second aspect of thepresent invention includes: a first magnetization pinned layer whichcomprises at least one magnetic layer and in which a magnetizationdirection is pinned; a magnetization free layer in which a magnetizationdirection is changeable; a tunnel barrier layer provided between thefirst magnetization pinned layer and the magnetization free layer; anon-magnetic metal layer provided on a first region in an oppositesurface of the magnetization free layer from the tunnel barrier layer; adielectric layer provided on a second region other than the first regionin the opposite surface of the magnetization free layer from the tunnelbarrier layer; and a second magnetization pinned layer which comprisesat least one magnetic layer and in which a magnetization direction ispinned, the second magnetization pinned layer being provided on anopposite surface of the non-magnetic metal layer from the magnetizationfree layer.

An interface between the dielectric layer and the magnetization freelayer and an interface between the non-magnetic metal layer and themagnetization free layer can be substantially coplanar.

An interface between the dielectric layer and the magnetization freelayer can be located nearer an interface between the tunnel barrierlayer and the magnetization free layer than an interface between thenon-magnetic metal layer and the magnetization free layer.

A magnetoresistive effect element according to a third aspect of thepresent invention includes: a first magnetization pinned layer whichincludes at least one magnetic layer and in which a magnetizationdirection is pinned; a magnetization free layer in which a magnetizationdirection is changeable; a tunnel barrier layer provided between thefirst magnetization pinned layer and the magnetization free layer; anon-magnetic metal layer provided on an opposite surface of themagnetization free layer from the tunnel barrier layer; a dielectriclayer provided on a first region in an opposite surface of thenon-magnetic metal layer from the magnetization free layer; and a secondmagnetization pinned layer which includes at least one magnetic layerand in which a magnetization direction is pinned, the secondmagnetization pinned layer being provided so as to cover a second regionother than the first region in the opposite surface of the non-magneticmetal layer from the magnetization free layer and an opposite surface ofthe dielectric layer from the non-magnetic metal layer.

An interface between the dielectric layer and the second magnetizationpinned layer and an interface between the non-magnetic metal layer andthe second magnetization pinned layer can be substantially coplanar.

An interface between the dielectric layer and the second magnetizationpinned layer can be located farther from an interface between the tunnelbarrier layer and the magnetization free layer than an interface betweenthe non-magnetic metal layer and the second magnetization pinned layer.

The second magnetization pinned layer can have a three-layer structurein which a first magnetic layer, a first non-magnetic layer, and asecond magnetic layer are stacked in order from a side of thenon-magnetic metal layer, or a five-layer structure in which a firstmagnetic layer, a first non-magnetic layer, a second magnetic layer, asecond non-magnetic layer, and a third magnetic layer are stacked inorder from the side of the non-magnetic metal layer, and an interfacebetween the dielectric layer and the second magnetization pinned layerexists in the first magnetic layer.

A magnetoresistive effect element according to a fourth aspect of thepresent invention includes: a first magnetization pinned layer whichincludes at least one magnetic layer and in which a magnetizationdirection is pinned; a magnetization free layer in which a magnetizationdirection is changeable; a tunnel barrier layer provided between thefirst magnetization pinned layer and the magnetization free layer; anon-magnetic metal layer provided on an opposite surface of themagnetization free layer from the tunnel barrier layer; a dielectriclayer provided on a first region in an opposite surface of thenon-magnetic metal layer from the magnetization free layer; and a secondmagnetization pinned layer which includes at least one magnetic layerand in which a magnetization direction is pinned, the secondmagnetization pinned layer being provided on a second region other thanthe first region in the opposite surface of the non-magnetic metal layerfrom the magnetization free layer.

An interface between the non-magnetic metal layer and the dielectriclayer can be located nearer an interface between the tunnel barrierlayer and the magnetization free layer than an interface between thenon-magnetic metal layer and the second magnetization pinned layer.

A magnetoresistive effect element according to a fifth aspect of thepresent invention includes: a first magnetization pinned layer whichincludes at least one magnetic layer and in which a magnetizationdirection is pinned; a magnetization free layer in which a magnetizationdirection is changeable; a tunnel barrier layer provided between thefirst magnetization pinned layer and the magnetization free layer; adielectric layer provided on a first region in an opposite surface ofthe magnetization free layer from the tunnel barrier layer; anon-magnetic metal layer provided on a second region other than thefirst region in the opposite surface of the magnetization free layerfrom the tunnel barrier layer so as to cover an opposite surface of thedielectric layer from the magnetization free layer; and a secondmagnetization pinned layer which includes at least one magnetic layerand in which a magnetization direction is pinned, the secondmagnetization pinned layer being provided on an opposite surface of thenon-magnetic metal layer from the magnetization free layer.

An interface between the dielectric layer and the magnetization freelayer and an interface between the non-magnetic metal layer and themagnetization free layer can be substantially coplanar.

An interface between the dielectric layer and the magnetization freelayer can be located nearer an interface between the tunnel barrierlayer and the magnetization free layer than an interface between thenon-magnetic metal layer and the magnetization free layer.

An interface between the non-magnetic metal layer and the dielectriclayer can be located farther from an interface between the tunnelbarrier layer and the magnetization free layer than an interface betweenthe non-magnetic metal layer and the magnetization free layer.

A magnetoresistive effect element according to a sixth aspect of thepresent invention includes: a first magnetization pinned layer whichincludes at least one magnetic layer and in which a magnetizationdirection is pinned; a magnetization free layer in which a magnetizationdirection is changeable; a tunnel barrier layer provided between thefirst magnetization pinned layer and the magnetization free layer; anon-magnetic metal layer provided on an opposite surface of themagnetization free layer from the tunnel barrier layer; a secondmagnetization pinned layer which includes at least one magnetic layerand in which a magnetization direction is pinned, the secondmagnetization pinned layer being provided on an opposite surface of thenon-magnetic metal layer from the magnetization free layer; and adielectric layer which passes through the magnetization free layer andat least a part of the non-magnetic metal layer and which does not passthrough the second magnetization pinned layer.

A magnetization direction of a magnetic layer included in the firstmagnetization pinned layer and located nearest the magnetization freelayer can be substantially parallel to a magnetization direction of amagnetic layer included in the second magnetization pinned layer andlocated nearest the magnetization free layer, and the non-magnetic metallayer can include Ru, Ir, Os or an alloy of them.

A magnetization direction of a magnetic layer included in the firstmagnetization pinned layer and located nearest the magnetization freelayer can be substantially antiparallel to a magnetization direction ofa magnetic layer included in the second magnetization pinned layer andlocated nearest the magnetization free layer, and the non-magnetic metallayer can include Cu, Ag, Au, Rh, Ir, or an alloy of them.

The dielectric layer and the tunnel barrier layer can include Al₂O₃,SiO₂, MgO, AlN, SiON, or AlON.

At least one of the first and second magnetization pinned layers canhave a three-layer structure comprising a magnetic layer/a non-magneticlayer/a magnetic layer, or a five-layer structure comprising a magneticlayer/a non-magnetic layer/a magnetic layer/a non-magnetic layer/amagnetic layer.

A magnetic memory according to a seventh aspect of the present inventionincludes: a memory cell including a magnetoresistive effect elementabove-described; a first wiring electrically connected to one end of themagnetoresistive effect element; and a second wiring electricallyconnected to the other end of the magnetoresistive effect element.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a magnetoresistive effort elementaccording to a first embodiment of the present invention;

FIG. 2 is a sectional view showing a magnetoresistive effort elementaccording to a first modification of the first embodiment;

FIG. 3 is a sectional view showing a magnetoresistive effort elementaccording to a second modification of the first embodiment;

FIG. 4 is a sectional view showing a magnetoresistive effort elementaccording to a third modification of the first embodiment;

FIG. 5 is a sectional view showing a magnetoresistive effort elementaccording to a fourth modification of the first embodiment;

FIG. 6 is a sectional view showing a magnetoresistive effort elementaccording to a fifth modification of the first embodiment;

FIG. 7 is a sectional view showing a magnetoresistive effort elementaccording to a sixth modification of the first embodiment;

FIG. 8 is a sectional view showing a magnetoresistive effort elementaccording to a seventh modification of the first embodiment;

FIG. 9 is a sectional view showing a magnetoresistive effort elementaccording to a second embodiment;

FIG. 10 is a sectional view showing a magnetoresistive effort elementaccording to a first modification of the second embodiment;

FIG. 11 is a sectional view showing a magnetoresistive effort elementaccording to a second modification of the second embodiment;

FIG. 12 is a sectional view showing a magnetoresistive effort elementaccording to a third modification of the second embodiment;

FIG. 13 is a sectional view showing a magnetoresistive effort elementaccording to a third embodiment;

FIG. 14 is a sectional view showing a magnetoresistive effort elementaccording to a fourth embodiment;

FIG. 15 is a sectional view showing a magnetoresistive effort elementaccording to a first modification of the fourth embodiment;

FIG. 16 is a sectional view showing a magnetoresistive effort elementaccording to a second modification of the fourth embodiment;

FIG. 17 is a sectional view showing a magnetoresistive effort elementaccording to a third modification of the fourth embodiment;

FIG. 18 is a sectional view showing a magnetoresistive effort elementaccording to a fifth embodiment;

FIG. 19 is a sectional view showing a magnetoresistive effort elementaccording to a first modification of the fifth embodiment;

FIG. 20 is a sectional view showing a magnetoresistive effort elementaccording to a second modification of the fifth embodiment;

FIG. 21 is a sectional view showing a magnetoresistive effort elementaccording to a third example of the fifth embodiment;

FIG. 22 is a sectional view showing a magnetoresistive effort elementaccording to a sixth embodiment;

FIG. 23 is a sectional view showing a magnetic memory according to aseventh embodiment of the present invention;

FIG. 24 is a sectional view showing a magnetic memory according to amodification of the seventh embodiment;

FIG. 25 is a sectional view showing a magnetic memory according to aneighth embodiment of the present invention;

FIG. 26 is a sectional view showing a magnetic memory according to amodification of the eighth embodiment;

FIG. 27 is a sectional view showing a magnetoresistive effect elementaccording to a comparative example;

FIG. 28 is a sectional view showing a magnetoresistive effect elementaccording to a comparative example;

FIG. 29 is a diagram showing spin inversion characteristics of a firstsample according to a first example and a first comparison sample of acomparison example at time of writing;

FIG. 30 is a diagram showing spin inversion characteristics of a secondsample according to a first example and a second comparison sample of acomparison example at time of writing;

FIG. 31 is a horizontal sectional view showing an example of anarrangement relation between a non-magnetic metal layer and adielectric;

FIG. 32 is a horizontal sectional view showing another example of anarrangement relation between a non-magnetic metal layer and adielectric;

FIG. 33 is a sectional view showing a magnetoresistive effect elementaccording to an eighth modification of the first embodiment;

FIG. 34 is a sectional view showing a magnetoresistive effect elementaccording to a ninth modification of the first embodiment;

FIG. 35 is a sectional view showing a magnetoresistive effect elementaccording to a tenth modification of the first embodiment; and

FIG. 36 is a sectional view showing a magnetoresistive effect elementaccording to an eleventh modification of the first embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Hereafter, embodiments of the present invention will be described indetail with reference to the drawings.

First Embodiment

A magnetoresistive effect element according to a first embodiment of thepresent invention is shown in FIG. 1. The magnetoresistive effectelement 1 according to this embodiment includes an antiferromagneticlayer 4 provided on an underlying layer 2, a first magnetization pinnedlayer 6 including a magnetic layer provided on the antiferromagneticlayer 4, in which the direction of magnetization (spin) is pinned byexchange coupling force to the antiferromagnetic layer 4, a tunnelbarrier layer 8 provided on the first magnetization pinned layer 6, amagnetization free layer (magnetic recording layer) 10 having achangeable magnetization direction provided on the tunnel barrier layer8, a second magnetization pinned layer 14 provided on the magneticrecording layer 10 so as to include a non-magnetic metal layer 12, whichis divided by a dielectric 11 at least on its interface side in contactwith the magnetic recording layer 10, and a magnetic layer provided onthe non-magnetic metal layer and having the magnetization of whichdirection is pinned, an antiferromagnetic layer 16 provided on thesecond magnetization pinned layer 14 to pin the direction ofmagnetization in the second magnetization pinned layer 14 by usingexchange coupling force, and a metal hard mask or metal protection film18 provided on the antiferromagnetic layer 16.

A horizontal sectional view taken near an interface between thenon-magnetic metal layer 12 and the magnetic recording layer 10 (asectional view at a plane parallel to the interface) is shown in FIG.31. As appreciated from FIG. 31, the non-magnetic metal layer 12 isdivided by the dielectric 11 on its magnetic recording layer 10 side.However, the non-magnetic metal layer 12 is not divided by thedielectric 11 on its second magnetization pinned layer 14 side. In otherwords, a part of the non-magnetic metal layer is divided by thedielectric 11. Since at least a part of the non-magnetic metal layer isthus divided by the dielectric 11, a current flowing through thenon-magnetic metal layer 12 flows through a place which is not dividedby the dielectric 11, in a concentrative manner. Therefore, thenon-magnetic metal layer 12 is referred to as current concentration typenon-magnetic layer as well. By the way, as appreciated from FIG. 1, aninterface between the dielectric 11 and the magnetization free layer 10and an interface between the non-magnetic metal player 12 and themagnetization free layer 10 are substantially coplanar. An oppositesurface of the dielectric 11 from the magnetization free layer 10 doesnot reach a surface between the non-magnetic metal layer 12 and thesecond magnetization pinned layer 14.

Furthermore, in the present embodiment, the first magnetization pinnedlayer 6 and the second magnetization pinned layer 14 are substantiallyparallel to each other in magnetization direction. In addition, thenon-magnetic metal layer 12 is formed of Ru, Ir, Os or an alloy of them.Here, “directions of magnetization are parallel” means that “directionsof magnetization are the same.” “Directions of magnetization areantiparallel” means that “directions of magnetization are opposite.”

In a structure like the magnetoresistive effect element of the presentembodiment, the magnetic recording layer 10 is subjected to two kinds oftorque, i.e., spin torque caused by spin-polarized electrons that havetunneled the tunnel barrier layer 8, and torque caused by spin-polarizedelectrons reflected by the current concentration type non-magnetic layer12.

If the non-magnetic layer 12 is not divided by the dielectric, butformed of a continuous film, then the resistance difference between thetunnel barrier layer and the non-magnetic metal layer 12 becomes toolarge and consequently the effect of spin reflection is reduced and thecurrent density is not reduced so much.

On the other hand, the effect of the spin reflection is made moreremarkable and the spin inversion current density is reduced by makingthe resistance of the tunnel barrier layer 8 nearly equal to theresistance of the current concentration type non-magnetic layer 12. Itis desirable to make the film thickness of the dielectric 11 whichdivides a part of the current concentration type non-magnetic layer 12equal to at least the film thickness of the tunnel barrier layer 8 inorder to make the resistance of the tunnel barrier layer 8 nearly equalto the resistance of the current concentration type non-magnetic layer12.

In general, the spin injection writing principle of an ordinary GMRelement obtained by laminating a magnetization pinned layer/anon-magnetic layer/a magnetic recording layer, and an ordinary tunneljunction element obtained by laminating a magnetization pinned layer/atunnel barrier layer/a magnetic recording layer will be describedhereafter.

a) In the case where the spin moment of the magnetization pinned layerand the magnetic recording layer is spin-inverted from antiparallel toparallel:

Electrons are injected from the magnetization pinned layer side, andelectrons spin-polarized in the magnetization pinned layer tunnel thetunnel barrier layer (or the non-magnetic layer) and exert spin torqueon the magnetic recording layer. As a result, the spin of the magneticrecording layer are inverted from antiparallel to parallel.

b) In the case where the spin moment of the magnetization pinned layerand the magnetic recording layer is spin-inverted from parallel toantiparallel:

Electrons are injected from the magnetic recording layer, and electronsspin-polarized in the magnetization pinned layer tunnel the tunnelbarrier layer. At that time, electrons having the same spin direction asthat of the magnetization pinned layer have a high tunnel probabilityand tunnel easily. However, the antiparallel spin is reflected.Electrons reflected to the magnetic recording layer exert spin torque onthe magnetic recording layer. Thus, the spin of the magnetic recordinglayer is inverted from parallel to antiparallel.

The current required at this time can be represented by the followingexpressions.

In the case of antiparallel to parallel:IC ^(P) =eαMA _(t) [H−H _(k)−2πM]/hg(π)

In the case of parallel to antiparallel:IC ^(AP) =eαMA _(t) [H+ H _(k)+2πM]/hg(0)

Here, e is the elementary charge, α is the Gilbert damping parameter, Mis magnetization, A_(t) is the volume of the magnetic recording layer, His the magnetic field, H_(k) is the anisotropy constant, and h is thePlank's constant. Furthermore, g(π) and g(0) depend upon the spin at theinterface between the magnetization pinned layer and the non-magneticlayer, and they are given by the following equation.g(θ)=[−4+(1+p)³(3+cos θ)/4 p ^(3/2)]⁻¹

Here, p is a spin polarization factor. From this equation, it followsthat g(π)>g(0). In general, therefore, the current IC^(P) in the casewhere the spin is inverted from antiparallel to parallel is smaller thanthe current IC^(AP) in the case where the spin is inverted from parallelto antiparallel.

For example, when letting flow a spin injection current from the metalprotection film 18 toward the underlying layer 2 in the magnetoresistiveeffect element 1 shown in FIG. 1, electrons are injected from the firstmagnetization pinned layer 6 into the magnetic recording layer 10, andelectrons spin-polarized in the same direction as the magnetic moment ofthe first magnetization pinned layer by the first magnetization pinnedlayer pass through the tunnel barrier layer 8 and provide the magneticrecording layer 10 with spin torque. In addition, electrons are injectedinto the second magnetization pinned layer 14 via the magnetic recordinglayer 10 and the non-magnetic metal layer 12. By selecting theabove-described material (any one of Ru, Ir, Os, or an alloy of them) asthe material of the non-magnetic metal layer 12, electrons having thespin that is the same in direction as the magnetic moment of the secondmagnetization pinned layer 14 are reflected by the second magnetizationpinned layer 14, and injected into the magnetic recording layer 10 againas reflected spin electrons. As a result, the magnetization direction ofthe magnetic recording layer 10 becomes the same as (parallel to) thatof the first magnetization pinned layer 6.

When letting flow a spin injection current from the underlying layer 2toward the metal protection film 18, electrons are injected from thesecond magnetization pinned layer 14 into the magnetic recording layer10 via the non-magnetic metal layer 12. By selecting the above-describedmaterial as the material of the non-magnetic metal layer 12, electronshaving a spin opposite to the magnetic moment of the secondmagnetization pinned layer 14 become dominant when electronsspin-polarized in the second magnetization pinned layer 14 pass throughthe non-magnetic metal layer 12. The spin-polarized electrons providethe magnetic recording layer 10 with spin torque. In addition, thespin-polarized electrons attempt to flow from the magnetic recordinglayer 10 to the first magnetization pinned layer 6 via the tunnelbarrier layer 8. When passing through the tunnel barrier layer 8,however, electrons having a spin opposite to the magnetic moment of thefirst magnetization pinned layer 6 are reflected because the tunnelprobability becomes low. The electrons having the spin opposite to themagnetic moment of the first magnetization pinned layer 6 provide themagnetic recording layer 10 with spin torque again as reflected spinelectrons. As a result, the magnetization direction of the magneticrecording layer 10 becomes opposite to (antiparallel to) that of thefirst magnetization pinned layer 6.

In the present embodiment having the current concentration typenon-magnetic layer 12 shown in FIG. 1, the resistance of thenon-magnetic metal layer 12 is regulated. As a result, the reflectedspin electrons also exert spin torque on the magnetic recording layer asdescribed above. The current density is reduced, and the current in thecase where spin inversion from parallel to antiparallel is conducted andthe current in the case where spin inversion from antiparallel toparallel is conducted become nearly equal low values. Therefore, it ispossible to obtain a highly reliable magnetoresistive effect elementthat operates with low power consumption and low current writing andwithout element destruction.

In order to regulate the resistance of the non-magnetic metal layer 12,the non-magnetic metal layer 12 may be divided by the dielectric 11 notonly at the interface in contact with the magnetic recording layer 10but also on the second magnetization pinned layer 14 side as shown inFIG. 2. In other words, the non-magnetic metal layer 12 may be dividedby the dielectric 11 completely (first modification). The firstmodification has a configuration obtained by causing the interfacebetween the dielectric 11 and the second magnetization pinned layer 14provided on the opposite side from the magnetic recording layer 10 andthe interface between the non-magnetic metal layer 12 and the secondmagnetization pinned layer 14 to be coplanar. In the first modificationas well, effects similar to those in the present embodiment can beobtained.

Furthermore, in order to regulate the resistance, the dielectric 11 thatcompletely divide the non-magnetic metal layer 12 may divide a part ofthe second magnetization pinned layer 14 as shown in FIG. 3 as shown inFIG. 3 (second modification). In other words, the interface between thedielectric 11 and the second magnetization pinned layer 14 is locatedfarther from the interface between the tunnel barrier layer 8 and themagnetization free layer 10 than the interface between the non-magneticmetal layer 12 and the second magnetization pinned layer 14 asappreciated from FIG. 3. In the second modification as well, effectssimilar to those in the present embodiment can be obtained.

In order to adjust the resistance, the dielectric 11 that completelydivide the non-magnetic metal layer 12 may completely divide the secondmagnetization pinned layer 14 and the antiferromagnetic layer 16 asshown in FIG. 4 (third modification). In other words, the oppositesurface of the dielectric 11 from the magnetization free layer 10 andthe interface between the antiferromagnetic layer 16 and the metalprotection film 18 are substantially coplanar as appreciated from FIG.4. In the third modification as well, effects similar to those in thepresent embodiment can be obtained.

Furthermore, in order to regulate the resistance, the dielectric 11 maydivide a part of the magnetic recording layer 10 and a part of thenon-magnetic metal layer 12 as shown in FIG. 5 (fourth modification). Inother words, the opposite surface of the dielectric 11 from themagnetization free layer 10 is located nearer the second magnetizationpinned layer 14 than the interface between the non-magnetic metal layer12 and the magnetization free layer 10 as appreciated from FIG. 5. Inaddition, a surface of the dielectric 11 on the side of themagnetization free layer 10 is located nearer the tunnel barrier layer 8than the interface between the non-magnetic metal layer 12 and themagnetization free layer 10. In the fourth modification as well, effectssimilar to those in the present embodiment can be obtained.

In order to regulate the resistance, the dielectric 11 may divide a partof the magnetic recording layer 10 and completely the non-magnetic metallayer 12 as shown in FIG. 6 (fifth modification). In other words, theopposite surface of the dielectric 11 from the magnetization free layer10 and the interface between the non-magnetic metal layer 12 and thesecond magnetization pinned layer 14 are substantially coplanar asappreciated from FIG. 6. In addition, the surface of the dielectric 11on the side of magnetization free layer 10 is located nearer the tunnelbarrier layer 8 than the interface between the non-magnetic metal layer12 and the magnetization free layer 10. In the fifth modification aswell, effects similar to those in the present embodiment can beobtained.

Furthermore, in order to regulate the resistance, the dielectric 11 maydivide a part of the magnetic recording layer 10, completely divide thenon-magnetic metal layer 12, and divide a part of the secondmagnetization pinned layer 14 as shown in FIG. 7 (sixth modification).In other words, the opposite surface of the dielectric 11 from themagnetization free layer 10 is located farther from the interfacebetween the tunnel barrier layer 8 and the magnetization free layer 10than the interface between the non-magnetic metal layer 12 and themagnetization free layer 10 as appreciated from FIG. 7. In the sixthmodification as well, effects similar to those in the present embodimentcan be obtained.

In order to regulate the resistance, the dielectric 11 may divide a partof the magnetic recording layer 10 and completely divide thenon-magnetic metal layer 12, the second magnetization pinned layer 14and the antiferromagnetic layer 16 as shown in FIG. 8 (seventhmodification). In other words, the opposite surface of the dielectric 11from the magnetization free layer 10 and the interface between theantiferromagnetic layer 16 and the metal protection film 18 aresubstantially coplanar as appreciated from FIG. 8. In addition, thesurface of the dielectric 11 on the side of the magnetization free layer10 is located nearer the tunnel barrier layer 8 than the interfacebetween the non-magnetic metal layer 12 and the magnetization free layer10. In the seventh modification as well, effects similar to those in thepresent embodiment can be obtained.

In the fourth and fifth modifications respectively shown in FIG. 5 andFIG. 6, the dielectric 11 divides a part of the magnetic recording layer10. In order to regulate the resistance, however, the dielectric 11 maycompletely divide the magnetic recording layer 10 as shown in FIG. 33and FIG. 34 (eighth and ninth modifications). In the eighth and ninthmodifications, effects similar to those in the present embodiment can beobtained. In the eighth modification shown in FIG. 33, the dielectric 11passes through the magnetic recording layer 10 and a part of thenon-magnetic metal layer 12. However, the dielectric 11 does not passthrough the second magnetization pinned layer 14.

Furthermore, in the present embodiment shown in FIG. 1 and the firstmodification shown in FIG. 2, the interface between the non-magneticmetal layer 12 and the magnetic recording layer 10 and the interfacebetween the dielectric 11 and the magnetic recording layer 10 aresubstantially coplanar. In order to regulate the resistance, however,the interface between the non-magnetic metal layer 12 and the magneticrecording layer 10 may be located nearer the interface between themagnetic recording layer 10 and the tunnel barrier layer 8 than theinterface between the dielectric 11 and the magnetic recording layer 10as shown in FIG. 35 and FIG. 36 (tenth and eleventh modifications). Inthe tenth and eleventh modifications as well, effects similar to thosein the present embodiment can be obtained.

Second Embodiment

A magnetoresistive effect element 1A according to a second embodiment ofthe present invention is shown in FIG. 9. The magnetoresistive effectelement 1A according to the present embodiment has a configurationobtained by replacing the first magnetization pinned layer 6 in themagnetoresistive effect element 1 according to the first embodimentshown in FIG. 1 with a synthetic first magnetization pinned layer 6Ahaving a three-layer structure which includes a magnetic layer 6 ₁, anon-magnetic layer 6 ₂ and a magnetic layer 6 ₃, and replacing thesecond magnetization pinned layer 14 with a synthetic secondmagnetization pinned layer 14A having a three-layer structure whichincludes a magnetic layer 14 ₁, a non-magnetic layer 14 ₂ and a magneticlayer 14 ₃. The magnetic layer 6 ₁ is pinned in magnetization directionby the antiferromagnetic layer 4. The magnetic layer 6 ₃ is coupled tothe magnetic layer 6 ₁ antiferromagntically via the non-magnetic layer 6₂. The magnetic layer 14 ₃ is pinned in magnetization direction by theantiferromagnetic layer 16. The magnetic layer 14 ₁ is coupled to themagnetic layer 14 ₃ antiferromagntically via the non-magnetic layer 14₂.

In the present embodiment, the magnetic layer 6 ₃ included in the firstmagnetization pinned layer 6A and located nearest the magnetic recordinglayer 10 is substantially parallel in magnetization direction to themagnetic layer 14 ₁ included in the second magnetization pinned layer14A and located nearest the magnetic recording layer 10.

It is desirable to use such a synthetic magnetization pinned layer,because the magnetization pinning becomes firmer and the first andsecond magnetization pinned layers become more stable when spininjection writing is conducted.

By the way, the synthetic magnetization pinned layer may be one of thefirst and second magnetization pinned layers.

In the present embodiment as well, it is possible to obtain a highlyreliable magnetoresistive effect element that operates with low powerconsumption and low current writing and without element destruction, inthe same way as the first embodiment.

In order to regulate the resistance of the non-magnetic metal layer 12,the non-magnetic metal layer 12 may be divided by the dielectric 11 notonly at the interface in contact with the magnetic recording layer 10but also on the second magnetization pinned layer 14 side as shown inFIG. 10. In other words, the non-magnetic metal layer 12 may be dividedby the dielectric 11 completely (first modification). In the firstmodification as well, effects similar to those in the present embodimentcan be obtained.

Furthermore, in order to regulate the resistance, the dielectric 11 thatcompletely divides the non-magnetic metal layer 12 may divide a part ofthe magnetic layer 14 ₁ in the second magnetization pinned layer 14A asshown in FIG. 11 (second modification). In the second modification aswell, effects similar to those in the present embodiment can beobtained.

In order to regulate the resistance, the dielectric 11 that completelydivides the non-magnetic metal layer 12 may completely divide the secondmagnetization pinned layer 14 and the antiferromagnetic layer 16 asshown in FIG. 12 (third modification). In the third modification aswell, effects similar to those in the present embodiment can beobtained.

In the present embodiment and its first to third modifications as well,the dielectric 11 may divide a part of the magnetic recording layer 10in the same way as the fourth to seventh modifications of the firstembodiment respectively shown in FIGS. 5 to 8. The dielectric 11 maycompletely divide the magnetic recording layer 10 in the same way as theeighth and ninth modifications of the first embodiment. The interfacebetween the non-magnetic metal layer 12 and the magnetic recording layer10 may be located nearer the interface between the magnetic recordinglayer 10 and the tunnel barrier layer 8 than the interface between thedielectric 11 and the magnetic recording layer 10 in the same way as thetenth and eleventh modifications of the first embodiment. In these casesas well, effects similar to those in the present embodiment can beobtained.

Third Embodiment

A magnetoresistive effect element according to a third embodiment of thepresent invention will now be described with reference to FIG. 13. Themagnetoresistive effect element according to the present embodiment hasa configuration in which the non-magnetic metal layer 12 is not dividedby the dielectric 11 on the magnetic recording layer 10 side, butdivided by the dielectric 11 on the second magnetization pinned layer 14side in the magnetoresistive effect element according to the firstembodiment shown in FIG. 1 (see FIG. 13).

In the present embodiment as well, at least a part of the non-magneticmetal layer 12 is divided by the dielectric 11 and consequently thecurrent flowing through the non-magnetic metal layer 12 flows through aplace that is not divided by the dielectric 11 in a concentrative mannerin the same way as the first embodiment.

In the present embodiment as well, therefore, it becomes possible toadjust the resistance and it is possible to obtain a highly reliablemagnetoresistive effect element that operates with low power consumptionand low current writing and without element destruction in the same wayas the first embodiment.

By the way, it is desirable that the distance between the bottom surfaceof the dielectric 11 and the magnetic recording layer 10 isapproximately 1 nm.

The structure having a distance between the bottom surface of thedielectric 11 and the magnetic recording layer 10 as in the presentembodiment may be used in the magnetoresistive effect elements accordingto the first embodiment, the second and third modifications of the firstembodiment, the second embodiment, and the second and thirdmodifications of the second embodiment as well.

Fourth Embodiment

A magnetoresistive effect element according to a fourth embodiment ofthe present invention is shown in FIG. 14. A magnetoresistive effectelement 1B according to the present embodiment has a configurationobtained by replacing the second magnetization pinned layer 14 in themagnetoresistive effect element 1A according to the first embodimentshown in FIG. 1 with a second magnetization pinned layer 15 having asynthetic structure. The second magnetization pinned layer 15 having thesynthetic structure includes a magnetic layer 15 ₁ provided on thenon-magnetic metal layer (current concentration type non-magnetic layer)12, a non-magnetic layer 15 ₂ provided on the magnetic layer 15 ₁, and amagnetic layer 15 ₃ pinned in magnetization by exchange coupling to theantiferromagnetic layer 16. The magnetic layer 15 ₁ is coupledferromagnetically to the magnetic layer 15 ₃ via the non-magnetic layer15 ₂. In the present embodiment, the direction of magnetization of thefirst magnetization pinned layer 6 is substantially antiparallel to thedirection of magnetization of the magnetic layer 15 ₁ included in thesecond magnetization pinned layer 15 and located nearest the magneticrecording layer 10. In addition, the non-magnetic metal layer 12 isformed any one of Cu, Ag, Au, Rh, Ir, or an alloy of them.

If a spin injection current is let flow from the metal protection film18 toward the underlying layer 2 in the structure according to thepresent embodiment, then spin-polarized electrons are injected from thefirst magnetization pinned layer 6 to the magnetic recording layer 10and the magnetic recording layer 10 is provided with spin torque. Inaddition, electrons are injected into the second magnetization pinnedlayer 15 via the magnetic recording layer 10 and the non-magnetic metallayer 12. By selecting the above-described material (any one of Cu, Ag,Au, Rh, Ir, or an alloy of them) as the material of the non-magneticmetal layer 12, electrons having a spin opposite to the magnetic momentof the second magnetization pinned layer 15 are reflected by the secondmagnetization pinned layer 15, and injected into the magnetic recordinglayer 10 as reflected spin electrons again. As a result, themagnetization direction of the magnetic recording layer 10 becomes thesame as (parallel to) that of the first magnetization pinned layer 6.

If a spin injection current is let flow from the underlying layer 2 tothe metal protection film 18, then spin-polarized electrons are injectedfrom the second magnetization pinned layer 15 to the magnetic recordinglayer 10 and the magnetic recording layer 10 is provided with spintorque. In addition, the spin-polarized electrons attempt to flow fromthe magnetic recording layer 10 to the first magnetization pinned layer6 via the tunnel barrier layer 8. When passing through the tunnelbarrier layer 8, however, electrons having a spin opposite to themagnetic moment of the first magnetization pinned layer 6 are reflectedbecause the tunnel probability becomes low. The electrons having thespin opposite to the magnetic moment of the first magnetization pinnedlayer 6 provide the magnetic recording layer 10 with spin torque againas reflected spin electrons. As a result, the magnetization direction ofthe magnetic recording layer 10 becomes the same as that of the secondmagnetization pinned layer 15 (antiparallel to the magnetizationdirection of the first magnetization pinned layer 6).

Especially, in the same way as the first embodiment, the resistance ofthe non-magnetic metal layer 12 is regulated. As a result, the reflectedspin electrons also exert spin torque on the magnetic recording layerand the current density is reduced. In addition, the current in the casewhere spin inversion from parallel to antiparallel is conducted and thecurrent in the case where spin inversion from antiparallel to parallelis conducted become nearly equal low values. Therefore, it is possibleto obtain a highly reliable magnetoresistive effect element thatoperates with low power consumption and low current writing and withoutelement destruction.

In order to regulate the resistance of the non-magnetic metal layer 12,the non-magnetic metal layer 12 may be divided by the dielectric 11 notonly at the interface in contact with the magnetic recording layer 10but also on the second magnetization pinned layer 15 side as shown inFIG. 15. In other words, the non-magnetic metal layer 12 may be dividedby the dielectric 11 completely (first modification). In the firstmodification as well, effects similar to those in the present embodimentcan be obtained.

Furthermore, as shown in FIG. 16, the dielectric 11 that completelydivides the non-magnetic metal layer 12 may divide a part of the secondmagnetization pinned layer 15 (in FIG. 16, a part of the magnetic layer15 ₁) in order to regulate the resistance (second modification). In thesecond modification as well, effects similar to those in the presentembodiment can be obtained.

In order to regulate the resistance, the dielectric 11 that completelydivides the non-magnetic metal layer 12 may completely divide the secondmagnetization pinned layer 15 and the antiferromagnetic layer 16 asshown in FIG. 17 (third modification). In the third modification aswell, effects similar to those in the present embodiment can beobtained.

In the fourth embodiment and its modifications, the second magnetizationpinned layer 15 has the synthetic structure. However, the secondmagnetization pinned layer 15 may be a magnetic layer of a single layer.In this case, it is necessary to select a material different from thematerial of the ferromagnetic layer 4 as the material of theferromagnetic layer 16.

In the fourth embodiment and its modifications, the dielectric 11 doesnot divide a part of the magnetic recording layer 10. However, thedielectric 11 may be configured so as to divide a part of the magneticrecording layer 10 in the same way as the fourth to seventhmodifications of the first embodiment respectively shown in FIGS. 5 to8.

Fifth Embodiment

A magnetoresistive effect element 1C according to a fifth embodiment ofthe present invention is shown in FIG. 18. The magnetoresistive effectelement 1C according to the present embodiment has a configurationobtained by replacing the first magnetization pinned layer 6 in themagnetoresistive effect element 1B according to the fourth embodimentshown in FIG. 14 with a synthetic first magnetization pinned layer 6Ahaving a three-layer structure which includes a magnetic layer 6 ₁, anon-magnetic layer 6 ₂ and a magnetic layer 6 ₃, and replacing thesecond magnetization pinned layer 15 with a synthetic secondmagnetization pinned layer 15A having a five-layer structure whichincludes a magnetic layer 15 ₁, a non-magnetic layer 15 ₂, a magneticlayer 15 ₃, a non-magnetic layer 15 ₄, and a magnetic layer 15 ₅. Themagnetic layer 6 ₁ is pinned in magnetization direction by theantiferromagnetic layer 4. The magnetic layer 6 ₃ is coupled to themagnetic layer 6 ₁ antiferromagntically via the non-magnetic layer 6 ₂.The magnetic layer 15 ₅ is pinned in magnetization direction by theantiferromagnetic layer 16. The magnetic layer 15 ₃ is coupled to themagnetic layer 15 ₅ antiferromagntically via the non-magnetic layer 15₃. The magnetic layer 15 ₁ is coupled to the magnetic layer 15 ₃antiferromagntically via the non-magnetic layer 15 ₂.

In the present embodiment, the magnetic layer 6 ₃ included in the firstmagnetization pinned layer 6A and located nearest the magnetic recordinglayer 10 is substantially antiparallel in magnetization direction to themagnetic layer 15 ₁ included in the second magnetization pinned layer15A and located nearest the magnetic recording layer 10.

It is desirable to use such a synthetic magnetization pinned layer,because the magnetization pinning becomes firmer and the first andsecond magnetization pinned layers become more stable when spininjection writing is conducted. Furthermore, if such a magnetoresistiveeffect element is used as a memory element, interaction between bits isalso reduced. In addition, the leak magnetic field can be suppressed tothe minimum by adjusting magnitudes of magnetization (moments) ofmagnetic layers in the first and second magnetization pinned layers bymeans of film thicknesses and materials of the magnetic layer and thenon-magnetic layer.

In the present embodiment as well, it is possible to obtain a highlyreliable magnetoresistive effect element that operates with low powerconsumption and low current writing and without element destruction, inthe same way as the first embodiment.

In order to regulate the resistance of the non-magnetic metal layer 12,the non-magnetic metal layer 12 may be divided by the dielectric 11 notonly at the interface in contact with the magnetic recording layer 10but also on the second magnetization pinned layer 15 side as shown inFIG. 19. In other words, the non-magnetic metal layer 12 may be dividedby the dielectric 11 completely (first modification). In the firstmodification as well, effects similar to those in the present embodimentcan be obtained.

Furthermore, as shown in FIG. 20, the dielectric 11 that completelydivides the non-magnetic metal layer 12 may divide a part of the secondmagnetic pinned layer 15 (in FIG. 20, a part of the magnetic layer 15 ₁)in order to regulate the resistance (second modification). In the secondmodification as well, effects similar to those in the present embodimentcan be obtained.

In order to regulate the resistance, the dielectric 11 that completelydivides the non-magnetic metal layer 12 may completely divide the secondmagnetization pinned layer 15 and the antiferromagnetic layer 16 asshown in FIG. 21 (third modification). In the third modification aswell, effects similar to those in the present embodiment can beobtained.

In the present embodiment and its first to third modifications as well,the dielectric 11 may divide a part of the magnetic recording layer 10in the same way as the fourth to seventh modifications of the firstembodiment respectively shown in FIGS. 5 to 8. In these cases as well,effects similar to those in the present embodiment can be obtained.

Sixth Embodiment

A magnetoresistive effect element according to a sixth embodiment of thepresent invention will now be described with reference to FIG. 22. Themagnetoresistive effect element according to the present embodiment hasa configuration in which the non-magnetic metal layer 12 is not dividedby the dielectric 11 on the magnetic recording layer 10 side, butdivided by the dielectric 11 on the second magnetization pinned layer 15side in the magnetoresistive effect element according to the fourthembodiment shown in FIG. 14 (see FIG. 22).

In the present embodiment as well, at least a part of the non-magneticmetal layer 12 is divided by the dielectric 11 and consequently thecurrent flowing through the non-magnetic metal layer 12 flows through aplace that is not divided by the dielectric 11 in a concentrative mannerin the same way as the fourth embodiment.

In the present embodiment as well, therefore, it becomes possible toregulate the resistance and it is possible to obtain a highly reliablemagnetoresistive effect element that operates with low power consumptionand low current writing and without element destruction in the same wayas the first embodiment.

By the way, it is desirable that the distance between the bottom surfaceof the dielectric 11 and the magnetic recording layer 10 isapproximately 1 nm.

The structure having a distance between the bottom surface of thedielectric 11 and the magnetic recording layer 10 as in the presentembodiment may be used in the magnetoresistive effect elements accordingto the fourth embodiment, the second and third modifications of thefourth embodiment, the fifth embodiment, and the second and thirdmodifications of the fifth embodiment as well.

Seventh Embodiment

A magnetic memory according to a seventh embodiment according to thepresent invention is shown in FIG. 23. The magnetic memory according tothe present embodiment includes at least one memory cell. This memorycell includes the magnetoresistive effect element 1A according to thesecond embodiment and a selection transistor 60. The magnetoresistiveeffect element 1A includes an underlying layer 2 provided on a leadingelectrode 40, an antiferromagnetic layer 4 provided on the underlyinglayer 2, a first magnetization pinned layer 6A provided on theantiferromagnetic layer 4, a tunnel barrier layer 8 provided on thefirst magnetization pinned layer 6A, a magnetic-recording layer 10provided on the tunnel barrier layer 8, a non-magnetic metal layer 12provided on the magnetic recording layer 10 and partially divided by thedielectric 11, a second magnetization pinned layer 14A provided on thenon-magnetic metal layer 12, an antiferromagnetic layer 16 provided onthe second magnetization pinned layer 14A, and a metal protection film18 provided on the antiferromagnetic layer 16. By the way, a magneticlayer included in the first magnetization pinned layer 6A and locatednearest the magnetic recording layer 10 is substantially parallel inmagnetization direction to a magnetic layer included in the secondmagnetization pinned layer 14A and located nearest the magneticrecording layer 10.

The selection transistor 60 includes a gate electrode 61 and source anddrain regions 62 and 63 provided on respective sides of the gateelectrode. The metal protection film 18 is connected to a bit line 30used to select a memory cell. The leading electrode 40 is connected tothe source 62 of the selection transistor 60 via a connection part 50.The gate electrode 61 of the selection transistor 60 serves also as aword line used to select a memory cell. Therefore, the memory cell isprovided so as to be associated with a region where the bit line 30 andthe word line 61 intersect. The drain 63 of the selection transistor 60is connected to wiring 70.

Hereafter, the spin injection writing principle in this embodiment willbe described. First, a voltage is applied to the gate electrode 61 ofthe selection transistor 60 to turn on the selection transistor 60.

a) In the case where the spin moment of the first magnetization pinnedlayer 6A and the magnetic recording layer 10 is spin-inverted fromantiparallel to parallel:

Electrons are injected from the first magnetization pinned layer 6Aside, and electrons spin-polarized in the first magnetization pinnedlayer 6A tunnel the tunnel barrier layer 8 and the electrons areinjected into the magnetic recording layer 10. In addition, electronsthat have passed through the magnetic recording layer 10 are reflectedby the second magnetization pinned layer 14A, and injected into themagnetic recording layer 10 again as reflected spin electrons. As aresult, spin torque is exerted on the magnetic recording layer 10 andthe spin of the magnetic recording layer 10 are inverted fromantiparallel to parallel in the same way as the first embodiment.

b) In the case where the spin moment of the first magnetization pinnedlayer 6A and the magnetic recording layer 10 is spin-inverted fromparallel to antiparallel:

If electrons are injected from the second magnetization pinned layer 14Aside, then spin-polarized electrons that have passed through the secondmagnetization pinned layer 14A and the non-magnetic metal layer 12 areinjected into the magnetic recording layer 10. The electrons that havepassed through the magnetic recording layer 10 are reflected by thefirst magnetization pinned layer 6A via the tunnel barrier layer 8, andinjected into the magnetic recording layer 10 again as reflected spinelectrons. As a result, spin torque is exerted on the magnetic recordinglayer 10 and the spin of the magnetic recording layer 10 are invertedfrom parallel to antiparallel in the same way as the first embodiment.

The magnetic memory according to the present embodiment includes amagnetoresistive effect element 1A according to the second embodiment asthe memory element. Therefore, the magnetic memory becomes a highlyreliable magnetic memory that operates with low power consumption andlow current writing and without element destruction.

By the way, the volume of the first magnetization pinned layer 6A may bemade large in order to maintain the magnetization stability of themagnetization pinned layer at the time of spin writing as shown in FIG.24 (first modification). In this modification, the underlying layer 2,the antiferromagnetic layer 4, the first magnetization pinned layer 6and the tunnel barrier layer 8 in the magnetoresistive effect element 1Ashown in FIG. 23 are made large in size in film surface direction ascompared with the magnetic recording layer 10 as shown in FIG. 24.

In this modification as well, it is possible to obtain a highly reliablemagnetic memory that operates with low power consumption and low currentwriting and without element destruction in the same way as the seventhembodiment.

In the magnetic memory according to the present embodiment, themagnetoresistive effect element 1A according to the second embodiment isused as the memory element. However, the magnetoresistive effect elementaccording to any of the first embodiment, its modifications,modifications of the second embodiment, and the third embodiment may beused as the memory element. In these cases, it becomes possible tomaintain the magnetization stability of the magnetization pinned layerat the time of spin writing by making the volume of the firstmagnetization pinned layer large in the same way as the modification ofthe seventh embodiment shown in FIG. 24.

Eighth Embodiment

A magnetic memory according to an eighth embodiment according to thepresent invention is shown in FIG. 25. The magnetic memory according tothis embodiment has a configuration obtained by replacing themagnetoresistive effect element 1A in the magnetic memory according tothe seventh embodiment shown in FIG. 23 with the magnetoresistive effectelement 1C according to the fifth embodiment shown in FIG. 18. By theway, a magnetic layer included in the first magnetization pinned layer6A and located nearest the magnetic recording layer 10 is substantiallyantiparallel in magnetization direction to a magnetic layer included inthe second magnetization pinned layer 15A and located nearest themagnetic recording layer 10.

The magnetic memory according to this embodiment includes amagnetoresistive effect element 1C according to the fifth embodiment asthe memory element. Therefore, the magnetic memory becomes a highlyreliable magnetic memory that operates with low power consumption andlow current writing and without element destruction.

By the way, the volume of the first magnetization pinned layer 6A may bemade large in order to maintain the magnetization stability of themagnetization pinned layer at the time of spin writing as shown in FIG.26 (first modification). In this modification, the underlying layer 2,the antiferromagnetic layer 4, the first magnetization pinned layer 6and the tunnel barrier layer 8 in the magnetoresistive effect element 1Cshown in FIG. 25 are made large in size in film surface direction ascompared with the magnetic recording layer 10 as shown in FIG. 26.

In this modification as well, it is possible to obtain a highly reliablemagnetic memory that operates with low power consumption and low currentwriting and without element destruction in the same way as the eighthembodiment.

In the magnetic memory according to the present embodiment, themagnetoresistive effect element 1C according to the fifth embodiment isused as the memory element. However, the magnetoresistive effect elementaccording to any of the fourth embodiment, its modifications,modifications of the fifth embodiment, and the sixth embodiment may beused as the memory element. In these cases, it becomes possible tomaintain the magnetization stability of the magnetization pinned layerat the time of spin writing by making the volume of the firstmagnetization pinned layer large in the same way as the modification ofthe eighth embodiment shown in FIG. 26.

Furthermore, in the first to eighth embodiments and their modifications,it is necessary to design so as to make the volume of the whole magneticsubstance in the magnetic recording layer smaller than the volume of themagnetic substance in each of the first and second magnetization pinnedlayers. If design is conducted so as not to satisfy the relation as tothe volume of the magnetic substance, then the magnetization of themagnetization pinned layer becomes unstable due to the spin torque andfalse operation occurs.

In the first to eighth embodiments and their modifications, the magneticlayer in the magnetoresistive effect element is a thin film of at leastone kind or a multilayer film formed using a material selected from agroup including a Co—Fe alloy, a Co—Fe—Ni alloy, a (Co, Fe, Ni)-(Si, B)alloy, a (Co, Fe, Ni)-(B) amorphous alloy, and an amorphous materialsuch as a Co—(Zr, Hf, Nb, Ta, Ti) film, and a Heusler alloy such asCo₂(Cr—Fe)Al, Co₂MnAl and Co₂MnSi. The magnetic layer may be providedwith a Ni—Fe alloy such as a Permalloy alloy.

It is desirable that the magnetic layer has unidirectional anisotropy asthe magnetization pinned layer and has uniaxial anisotropy as themagnetic recording layer. Its thickness is desired to be in the range of0.1 nm to 100 nm. In addition, the magnetic layer (ferromagnetic layer)included in the magnetization pinned layer and the magnetic recordinglayer needs to have a thickness capable of preventing the magnetic layerfrom having super-paramagnetism. It is more desirable that the thicknessis 0.4 nm or more.

Furthermore, it is desirable to add an antiferromagnetic film to theferromagnetic layer used as the magnetization pinned layer to pin themagnetization. As such an antiferromagnetic film, magnetic substancessuch as a Fe (iron)—Mn (manganese) alloy, a Pt (platinum)—Mn (manganese)alloy, a Pt (platinum)—Cr (chromium)—Mn (manganese) alloy, a Ni(nickel)—Mn (manganese) alloy, an Ir (iridium)—Mn (manganese) alloy, NiO(nickel oxide), and CoO (cobalt oxide) can be mentioned.

It is possible to adjust magnetic characteristics and adjust variousphysical properties such as the crystal property, mechanicalcharacteristics, and chemical characteristics by adding non-magneticelements such as Ag (silver), Cu (copper), Au (gold), Al (aluminum), Mg(magnesium), Si (silicon), Bi (bismuth), Ta (tantalum), B (boron), C(carbon), O (oxygen), N (nitrogen), Pd (palladium), Pt (platinum), Zr(zirconium), Ir (iridium), W (tungsten), Mo (molybdenum), and Nb(niobium) to these magnetic substances.

Specifically, as a method for pinning the magnetic layer in onedirection, a laminated film having a three-layer structure includingCo(Co—Fe)/Ru (ruthenium)/Co(Co—Fe), a laminated film having athree-layer structure including Co(Co—Fe)/Ir (iridium)/Co(Co—Fe), alaminated film having a three-layer structure including Co(Co—Fe)/Os(osmium)/Co(Co—Fe), a laminated film having a three-layer structureincluding Co(Co—Fe)/Re (rhenium)/Co(Co—Fe), a laminated film having athree-layer structure including a Co—Fe—B amorphous material layer/Ru(ruthenium)/a Co—Fe—B amorphous material layer, a laminated film havinga three-layer structure including an amorphous material layer of Co—Fe—Bor the like/Ir (iridium)/an amorphous material layer of Co—Fe—B or thelike, a laminated film having a three-layer structure including anamorphous material layer of Co—Fe—B or the like/Os (osmium)/an amorphousmaterial layer of Co—Fe—B or the like, or a laminated film having athree-layer structure including an amorphous material layer of Co—Fe—Bor the like/Re (rhenium)/an amorphous material layer of Co—Fe—B or thelike is used. When these laminated films are used as the magnetizationpinned layer, it is desirable to provide an antiferromagnetic filmadjacent to the magnetization pinned layer. As the antiferromagneticfilm in this case as well, Fe—Mn, Pt—Mn, Pt—Cr—Mn, Ni—Mn, Ir—Mn, NiO,CoO or the like can be used in the same way as the foregoingdescription. If this structure is used, the magnetization in themagnetization pinned layer is more insusceptible to the influence of thecurrent magnetic field from the bit line or word line and themagnetization is pinned firmly. Furthermore, a stray field from themagnetization pinned layer can be weakened (or adjusted). And themagnetization shift of the magnetic recording layer can be adjusted bychanging the thickness of the two ferromagnetic layers that form themagnetization pinned layer.

As the magnetic recording layer, a two-layer structure represented as asoft magnetic layer/ferromagnetic layer or a three-layer structurerepresented as a ferromagnetic layer/a soft magnetic layer/aferromagnetic layer may also be used. A more favorable effect isobtained by controlling the intensity of interaction betweenferromagnetic layers using a three-layer structure represented as aferromagnetic layer/a non-magnetic layer/a ferromagnetic layer or afive-layer structure represented as a ferromagnetic layer/a non-magneticlayer/a ferromagnetic layer/a non-magnetic layer/a ferromagnetic layer.That is, it is not necessary to increase the power consumption of thecurrent magnetic field even if the cell width of the magnetic recordinglayer which is the memory cell is sub-micron or less. At this time, itdoesn't matter if the kind and film thickness of the ferromagnetic layerare changed.

In particular, if Co—Fe, Co—Fe—Ni, or Fe rich Ni—Fe having a large MRratio is used in the ferromagnetic layer located near the insulationbarrier (tunnel barrier layer) and Ni rich Ni—Fe, Ni rich Ni—Fe—Co orthe like is used in the ferromagnetic substance that is not in contactwith the tunnel barrier layer, then the switching magnetic field can beweakened while keeping the MR ratio at a large value. It is morefavorable.

In the magnetic recording layer as well, It is possible to adjustmagnetic characteristics and adjust various physical properties such asthe crystal property, mechanical characteristics, and chemicalcharacteristics by adding non-magnetic elements such as Ag (silver), Cu(copper), Au (gold), Al (aluminum), Ru (ruthenium), Os (osmium), Re(rhenium), Mg (magnesium), Si (silicon), Bi (bismuth), Ta (tantalum), B(boron), C (carbon), O (oxygen), N (nitrogen), Pd (palladium), Pt(platinum), Zr (zirconium), Ir (iridium), W (tungsten), Mo (molybdenum),and Nb (niobium) to these magnetic substances.

On the other hand, when a TMR element is used as the magnetoresistiveeffect element, it is possible to use various insulators (dielectrics)such as Al₂O₃ (aluminum oxide), SiO₂ (silicon oxide), MgO (magnesiumoxide), AlN (aluminum nitride), Bi₂O₃ (bismuth oxide), MgF₂ (magnesiumfluoride), CaF₂ (calcium fluoride), SrTiO₂ (titanium oxide strontium),AlLaO₃ (lanthanum oxide aluminum) and Al—N—O (aluminum oxide nitride),as the tunnel barrier layer (or dielectric layer) provided between themagnetization pinned layer and the magnetic recording layer.

It is not necessary that these compounds have a completely accuratecomposition from the view of stoichiometry. Loss, excess, orinsufficiency of oxygen, nitrogen, fluorine or the like may exist. It isdesirable that the thickness of the insulation layer (dielectric layer)is thin to the extent that the tunnel current flows. As a matter offact, it is desirable that the thickness is 10 nm or less.

Such a magnetoresistive effect element can be formed on a predeterminedsubstrate by using ordinary thin film forming means such as varioussputter methods, the evaporation method, or the molecular beam epitaxymethod. As the substrate in this case, various substrates such as Si(silicon), SiO₂ (silicon oxide), Al₂O₃ (aluminum oxide), spinel and AlN(aluminum nitride) substrates can be used.

Furthermore, a layer formed of Ta (tantalum), Ti (titanium), Pt(platinum), Pd (palladium), Au (gold), Ti (titanium)/Pt (platinum), Ta(tantalum)/Pt (platinum), Ti (titanium)/Pd (palladium), Ta (tantalum)/Pd(palladium), Cu (copper), Al (aluminum)—Cu (copper), Ru (ruthenium), Ir(iridium), or Os (osmium) may be provided on the substrate as theunderlying layer, protection layer or hard mask.

It is a matter of course that in the seventh and eighth embodiments asense current control element circuit, a driver and a sinker whichcontrol a sense current let flow through the magnetoresistive effectelement in order to read out information stored by the magnetoresistiveeffect element are further included.

In the above-described embodiments, the non-magnetic metal layer 12 andthe dielectric 11 have the pattern in which the non-magnetic metal layer12 is arranged in the dielectric 11 regularly as shown in FIG. 31 anddescribed with reference to the first embodiment. However, a pattern inwhich the non-magnetic metal layer 12 is arranged in the dielectric 11at random. Alternatively, a pattern in which the dielectric 11 isarranged in the non-magnetic metal layer 12 regularly as shown in FIG.32 or a pattern in which the dielectric 11 is arranged in thenon-magnetic metal layer 12 at random may be used.

Hereafter, examples of the present invention will be described in moredetail with reference to examples.

FIRST EXAMPLE

First, as a first example of the present invention, the magnetoresistiveeffect element 1A according to the second embodiment shown in FIG. 9 andthe magnetoresistive effect element 1B according to the fourthembodiment shown in FIG. 14 are fabricated as a first sample and asecond sample. As a comparative example, magnetoresistive effectelements having structures respectively shown in FIG. 27 and FIG. 28 arefabricated as a first comparative sample and a second comparative sampleat the same time. These samples are compared in terms of the spininversion current. In the magnetoresistive effect elements respectivelyhaving structures shown in FIG. 27 and FIG. 28, the non-magnetic metallayer is not divided by the dielectric, but is a continuous film unlikethe magnetoresistive effect elements shown in FIG. 9 and FIG. 14.

Hereafter, a structure of the magnetoresistive effect element accordingto the first example will be described along its manufacture procedure.

As the first sample, a TMR film, i.e., a laminated film including anunderlying layer/an antiferromagnetic layer/a magnetic layer/anon-magnetic layer/a magnetic layer/a tunnel barrier layer/a magneticlayer/a non-magnetic metal layer divided by a dielectric/a magneticlayer/a non-magnetic layer/a magnetic layer/an antiferromagnetic layer/acap layer formed of Ru (not illustrated)/a metal hard mask is formed ona lower electrode (not illustrated) provided on a substrate, as shown inFIG. 9.

As the second sample, a TMR film, i.e., a laminated film including anunderlying layer/an antiferromagnetic layer/a magnetic layer/a tunnelbarrier layer/a magnetic layer/a non-magnetic metal layer divided by adielectric/a magnetic layer/a non-magnetic layer/a magnetic layer/anantiferromagnetic layer/a cap layer formed of Ru (not illustrated)/ametal hard mask is formed on a lower electrode (not illustrated) asshown in FIG. 14.

As the first comparative sample, a TMR film, i.e., a laminated filmincluding an underlying layer/an antiferromagnetic layer/a magneticlayer/a non-magnetic layer/a magnetic layer/a tunnel barrier layer/amagnetic layer/a non-magnetic metal layer/a magnetic layer/anon-magnetic layer/a magnetic layer/an antiferromagnetic layer/a caplayer formed of Ru (not illustrated)/a metal hard mask is formed on alower electrode (not illustrated) as shown in FIG. 27.

As the second comparative sample, a TMR film, i.e., a laminated filmincluding an underlying layer/an antiferromagnetic layer/a magneticlayer/a tunnel barrier layer/a magnetic layer/a non-magnetic metallayer/a magnetic layer/a non-magnetic layer/a magnetic layer/anantiferromagnetic layer/a cap layer formed of Ru (not illustrated)/ametal hard mask is formed on a lower electrode (not illustrated) asshown in FIG. 28.

In the present example, all of lower wiring is formed of Ta/Cu/Ta andthe underlying layer is formed of Ru. In the TMR film of the firstsample, PtMn (14 nm) is used as the antiferromagnetic layer, Co₉₀Fe₁₀ (3nm)/Ru (0.85 nm)/Co₉₀Fe₁₀ (4 nm) is used as the first magnetizationpinned layer, AlOx (1.4 nm) is used as the tunnel barrier layer,(Co₉₀Fe₁₀)₈₀B₂₀ (3 nm) is used as the magnetic recording layer, AlOx(0.7 nm) is used as the dielectric which divides the non-magnetic metallayer, Ru (5 nm) is used as the non-magnetic metal layer, Co₉₀Fe₁₀ (4nm)/Ru (0.85 nm)/Co₉₀Fe₁₀ (3 nm) is used as the second magnetizationpinned layer, and PtMn (14 nm) is used as the antiferromagnetic layer inorder from the bottom. The numerical value in ( ) indicates the filmthickness.

In the TMR film of the second sample, PtMn (14 nm) is used as theantiferromagnetic layer, Co₉₀Fe₁₀ (3 nm) is used as the firstmagnetization pinned layer, AlOx (1.4 nm) is used as the tunnel barrierlayer, (Co₉₀Fe₁₀)₈₀B₂₀ (3 nm) is used as the magnetic recording layer,AlOx (0.7 nm) is used as the dielectric which divides the non-magneticmetal layer, Cu (5 nm) is used as the non-magnetic metal layer, Co₉₀Fe₁₀(4 nm)/Ru (0.85 nm)/Co₉₀Fe₁₀ (3 nm) is used as the second magnetizationpinned layer, and PtMn (14 nm) is used as the antiferromagnetic layer inorder from the bottom. The numerical value in ( ) indicates the filmthickness.

AlOx (0.7 nm) used as the dielectric which divides the non-magneticmetal layer is fabricated by forming a film of Al in an island form andthen conducting natural oxidation in si-tu. The tunnel barrier layerformed of AlOx (1.4 nm) is fabricated by forming a film of Al (0.7 nm)and conducting natural oxidation, and then forming a film of Al (0.7 nm)and conducting natural oxidation again. In other words, the dielectricwhich divides the magnetic recording layer, and the tunnel barrier layerare natural oxidation dielectrics.

In the TMR film of the first comparative sample according to acomparative example, PtMn (14 nm) is used as the antiferromagneticlayer, Co₉₀Fe₁₀ (3 nm)/Ru (0.85 nm)/Co₉₀Fe₁₀ (4 nm) is used as the firstmagnetization pinned layer, AlOx (1.4 nm) is used as the tunnel barrierlayer, (Co₉₀Fe₁₀)₈₀B₂₀ (3 nm) is used as the magnetic recording layer,Ru (5 nm) is used as the non-magnetic metal layer, Co₉₀Fe₁₀ (4 nm)/Ru(0.85 nm)/Co₉₀Fe₁₀ (3 nm) is used as the second magnetization pinnedlayer, and PtMn (14 nm) is used as the antiferromagnetic layer.

In the TMR film of the second comparative sample, PtMn (14 nm) is usedas the antiferromagnetic layer, Co₉₀Fe₁₀ (3 nm) is used as the firstmagnetization pinned layer, AlOx (1.4 nm) is used as the tunnel barrierlayer, (Co₉₀Fe₁₀)₈₀B₂₀ (3 nm) is used as the magnetic recording layer,Cu (5 nm) is used as the non-magnetic metal layer, Co₉₀Fe₁₀ (4 nm)/Ru(0.85 nm)/Co₉₀Fe₁₀ (3 nm) is used as the second magnetization pinnedlayer, and PtMn (14 nm) is used as the antiferromagnetic layer.

In all samples, a cap layer formed of Ru (5 nm) and a hard mask layerformed of Ta (300 nm) are formed on the top surface of the TMR film.

Thereafter, the TMR elements of the first example and the comparativeexample are annealed in a magnetic field at 270° C. Then the TMRelements are coated with a resist, and etching is conducted. Then theresist is subjected to slimming using an ozone flow at 140° C. Ta isetched using the slimmed resist as a mask and using SF₆ gas according tothe RIE method. This etching is stopped by the cap layer formed of Ru.Thereafter, the resist is peeled off. Junction separation of theferromagnetic tunnel junction is conducted using the Ta as a hard maskand using milling or the RIE (Reactive Ion Etching) method as far as thetunnel barrier layer. Both the first example and the comparative examplehave a junction size of 0.1×0.18 μm².

Thereafter, an SiOx protection film is formed, and coated with a resist.The resist is patterned to form a resist pattern. The lower electrode ispatterned using this resist pattern as a mask and using the RIE method.Thereafter, the resist pattern is removed, and an interlayer insulationfilm formed of SiOx is formed. Then, etching back and planarization areconducted. In addition, the Ta hard mask layer in the upper part of theTMR film is subjected to head exposure. Then, sputter etching isconducted, and wiring is sputtered. The wiring is formed by conductingetch back using the RIE method. Thereafter, a magnetic field is appliedto the long axis direction of the magnetic layer in order to conductannealing in the magnetic field.

A 200 nm pulse current is applied to the first sample, the firstcomparative sample, the second sample, and the second comparativesample, and a current (mA) at which the spin is inverted is checked. Asshown in FIG. 29 and FIG. 30, the spin is inverted at 0.15 mA in thefirst sample, at 0.5 mA in the first comparative sample, at 0.17 mA inthe second sample, and at 0.55 mA in the second comparative sample.Therefore, it is appreciated that the structure of the present exampleis suitable as a large capacity memory and spin injection writing can beconducted at a low current. As a result of repetitive measurements, spininjection writing up to the number of times of writing of 10⁶ can beascertained, and the reliability of the present structure can beascertained.

SECOND EXAMPLE

As a second example of the present invention, the magnetoresistiveeffect element 1A according to the first modification of the secondembodiment shown in FIG. 10 and the magnetoresistive effect element 1Baccording to the first modification of the fourth embodiment shown inFIG. 15 are fabricated respectively as a third sample and a fourthsample. As a comparative example, magnetoresistive effect elementshaving structures respectively shown in FIG. 27 and FIG. 28 arefabricated as a third comparative sample and a fourth comparative sampleat the same time. These samples are compared in terms of the spininversion current.

Hereafter, a structure of the magnetoresistive effect element accordingto the second example will be described along its manufacture procedure.

As the third sample, a TMR film, i.e., a laminated film including anunderlying layer/an antiferromagnetic layer/a magnetic layer/anon-magnetic layer/a magnetic layer/a tunnel barrier layer/a magneticlayer/a non-magnetic metal layer divided by a dielectric/a magneticlayer/a non-magnetic layer/a magnetic layer/an antiferromagnetic layer/acap layer formed of Ru (not illustrated)/a metal hard mask is formed ona lower electrode (not illustrated) provided on a substrate, as shown inFIG. 10. The TMR element corresponding to this configuration is used asthe third sample.

As the fourth sample, a TMR film, i.e., a laminated film including anunderlying layer/an antiferromagnetic layer/a magnetic layer/a tunnelbarrier layer/a magnetic layer/a non-magnetic metal layer divided by adielectric/a magnetic layer/a non-magnetic layer/a magnetic layer/anantiferromagnetic layer/a cap layer formed of Ru (not illustrated)/ametal hard mask is formed on a lower electrode (not illustrated) asshown in FIG. 15.

In the present example, all of lower wiring is formed of Ta/Cu/Ta andthe underlying layer is formed of Ru.

In the TMR film of the third sample, PtMn (14 nm) is used as theantiferromagnetic layer, Co₇₀Fe₃₀ (4 nm)/Ru (0.85 nm)/CO₇₀Fe₃₀ (4 nm) isused as the first magnetization pinned layer, MgO (1.0 nm) is used asthe tunnel barrier layer, (Co₇₀Fe₃₀)₈₀B₂₀ (3 nm) is used as the magneticrecording layer, AlOx is used as the dielectric layer which divides thenon-magnetic metal layer, Ru (5 nm) is used as the non-magnetic metallayer, Co₇₀Fe₃₀ (4 nm)/Ru (0.85 nm)/Co₇₀Fe₃₀ (3 nm) is used as thesecond magnetization pinned layer, and PtMn (14 nm) is used as theantiferromagnetic layer in order from the bottom.

In the TMR film of the fourth sample, PtMn (14 nm) is used as theantiferromagnetic layer, Co₇₀Fe₃₀ (4 nm) is used as the firstmagnetization pinned layer, MgO (1.0 nm) is used as the tunnel barrierlayer, (Co₇₀Fe₃₀)₈₀B₂₀ (3 nm) is used as the magnetic recording layer,AlOx (0.7 nm) is used as the dielectric which divides the non-magneticmetal layer, Au (5 nm) is used as the non-magnetic metal layer, Co₇₀Fe₃₀(4 nm)/Ru (0.85 nm)/Co₇₀Fe₃₀ (3 nm) is used as the second magnetizationpinned layer, and PtMn (14 nm) is used as the antiferromagnetic layer inorder from the bottom.

AlOx (0.7 nm) used as the dielectric which divides the non-magneticmetal layer is fabricated by using a patterned self-aligned process.Hereafter, the patterned self-aligned process will be described briefly.

In the TMR film of the third sample, the antiferromagnetic layer formedof PtMn (14 nm), the first magnetization pinned layer formed of Co₇₀Fe₃₀(4 nm)/Ru (0.85 nm)/Co₇₀Fe₃₀ (4 nm), the tunnel barrier layer formed ofMgO (1.0 nm), the magnetic recording layer formed of (Co₇₀Fe₃₀)₈₀B₂₀ (3nm), and the non-magnetic metal layer formed of Ru (5 nm) are formed inorder from the bottom.

In the TMR film of the fourth sample, the antiferromagnetic layer formedof PtMn (14 nm), the magnetization pinned layer formed of Co₇₀Fe₃₀ (4nm), the tunnel barrier layer formed of MgO (1.0 nm), the magneticrecording layer formed of (Co₇₀Fe₃₀)₈₀B₂₀ (3 nm), and the non-magneticmetal layer formed of Au (5 nm) are formed in order from the bottom.

Thereafter, diblock copolymer dissolved in an organic solvent is formedusing the spin coat method.

Subsequently, annealing is conducted in vacuum at a temperature in therange of approximately 140 to 200° C. for hours as long as approximately30 hours. Thereupon, phase separation is caused in diblock copolymer byself-organization during annealing. Sea-island structures each includinga diblock polymer portion having a size in the range of 15 to 30 nm arealigned at intervals of several tens nm.

Thereafter, the sample is exposed to oxygen plasma, and only the diblockpolymer portions are removed selectively. Holes are opened in portionswith the diblock polymer portions removed.

Subsequently, the sample is coated with SOG (spin on glass) diluted inlactic acid by using the spin coat method. SOG is embedded in the holes.The non-magnetic metal layer Ru or Au is patterned using an etching maskformed of SOG and ion milling.

In the pattern forming method using this self-organization phenomenon, apattern having a large area can be formed inexpensively in a short timeas compared with ordinary pattern forming methods such as the EBdrawing, photolithography, X-ray lithography, near-field opticallithography, interference exposure method, and FIB (Focused Ion Beam).The sea-island structures have a diameter in the range of approximately15 nm to 80 nm. A size conforming to the above-described condition canbe implemented.

Subsequently, immediately after the etching mask is removed, aprotection film formed of AlOx or SiOx is formed.

Subsequently, a film of Al₂O₃ is formed. The whole surface of the Al₂O₃film is coated with an OFR resist, and etch back is conducted to exposethe surface of the non-magnetic metal layer.

Subsequently, in the TMR film of the third sample, the magnetizationpinned layer formed of Co₇₀Fe₃₀ (4 nm)/Ru (0.85 nm)/Co₇₀Fe₃₀ (3 nm) andthe antiferromagnetic layer formed of PtMn (14 nm) are formed. In theTMR film of the fourth sample, the magnetization pinned layer formed ofCo₇₀Fe₃₀ (4 nm)/Ru (0.85 nm)/Co₇₀Fe₃₀ (3 nm) and the antiferromagneticlayer formed of PtMn (14 nm) are formed.

In all samples, the cap layer formed of Ru (5 nm) and the hard masklayer formed of Ta (300 nm) are formed. A subsequent processing methodis the same as that in the first example.

As a result, the magnetoresistive effect elements according to thepresent example are manufactured.

Furthermore, a third comparative sample and a fourth comparative sampleare fabricated. The third comparative sample and the fourth comparativesample are samples obtained by forming the non-magnetic metal layer inthe third sample and the fourth sample as a continuous film withoutconducting patterning.

Both the second example and the comparative example have a junction sizeof 0.1×0.18 μm². After the fabrication, a magnetic field is applied tothe long axis direction of the magnetic layer at 350° C. in order toconduct annealing in the magnetic field.

A 200 nm pulse current is applied to the third sample, the thirdcomparative sample, the fourth sample, and the fourth comparativesample, and a current (mA) at which the spin is inverted is checked. Asa result, the spin is inverted at 0.07 mA in the third sample, at 0.24mA in the third comparative sample, at 0.06 mA in the fourth sample, andat 0.28 mA in the fourth comparative sample. Therefore, it isappreciated that the structure of the present example is suitable as alarge capacity memory and spin injection writing can be conducted at alow current. As a result of repetitive measurements, spin injectionwriting up to the number of times of writing of 10⁶ can be ascertained,and the reliability of the present structure can be ascertained.

THIRD EXAMPLE Self-Aligned Process

As a third example of the present invention, the magnetoresistive effectelement 1A according to the second modification of the second embodimentshown in FIG. 11 and the magnetoresistive effect element 1C according tothe second modification of the fifth embodiment shown in FIG. 20 arefabricated respectively as a fifth sample and a sixth sample. As acomparative example, a magnetoresistive effect element having astructure shown in FIG. 27 is fabricated. In addition, in themagnetoresistive effect element having the structure shown in FIG. 28,the first magnetization pinned layer 6 is formed as a three-layerstructure represented as a magnetic layer/a non-magnetic layer/amagnetic layer and the second magnetization pinned layer 15 is formed asa five-layer structure represented as a magnetic layer/a non-magneticlayer/a magnetic layer/a non-magnetic layer/a magnetic layer. In thisway, a sixth comparative sample is fabricated. These samples arecompared in terms of the spin inversion current.

As to the structure of the magnetoresistive effect element according tothe third example, its manufacturing method is the same as that in thesecond example.

As the fifth sample, a TMR film, i.e., a laminated film including anunderlying layer/an antiferromagnetic layer/a magnetic layer/anon-magnetic layer/a magnetic layer/a tunnel barrier layer/a magneticlayer/a non-magnetic metal layer divided by a dielectric/a magneticlayer divided by a dielectric/a magnetic layer/a non-magnetic layer/amagnetic layer/an antiferromagnetic layer/a cap layer formed of Ru (notillustrated)/a metal hard mask is formed on a lower electrode (notillustrated) provided on a substrate, as shown in FIG. 11.

As the sixth sample, a TMR film, i.e., a laminated film including anunderlying layer/an antiferromagnetic layer/a magnetic layer/anon-magnetic layer/a magnetic layer/a tunnel barrier layer/a magneticlayer/a non-magnetic metal layer divided by a dielectric/a magneticlayer divided by a dielectric/a magnetic layer/a non-magnetic layer/amagnetic layer/a non-magnetic layer/a magnetic layer/anantiferromagnetic layer/a cap layer formed of Ru (not illustrated)/ametal hard mask is formed on a lower electrode (not illustrated) asshown in FIG. 20.

In the present example, all of lower wiring is formed of Ta/Cu/Ta andall of the underlying layer is formed of Ru. In the TMR film of thefifth sample, PtMn (14 nm) is used as the antiferromagnetic layer,Co₇₀Fe₃₀ (4 nm)/Ru (0.85 nm)/(Co₇₀Fe₃₀)₈₀B₂₀ (4 nm) is used as the firstmagnetization pinned layer, MgO (1.0 nm) is used as the tunnel barrierlayer, (Co₇₀Fe₃₀)₈₀B₂₀ (3 nm) is used as the magnetic recording layer,AlOx is used as the dielectric layer which divides the non-magneticmetal layer and the magnetic layer, Ru (5 nm) is used as thenon-magnetic metal layer divided by the dielectric, Co₇₀Fe₃₀ (3 nm) isused as the magnetic layer divided by the dielectric in the secondmagnetization pinned layer, Co₇₀Fe₃₀ (2 nm)/Ru (0.85 nm)/Co₇₀Fe₃₀ (3 nm)is used as the remaining second magnetization pinned layer, and PtMn (14nm) is used as the antiferromagnetic layer in order from the bottom.

In the TMR film of the sixth sample, PtMn (14 nm) is used as theantiferromagnetic layer, Co₇₀Fe₃₀ (3 nm)/Ru (0.85 nm)/(Co₇₀Fe₃₀)₈₀B₂₀ (4nm) is used as the first magnetization pinned layer, MgO (1.0 nm) isused as the tunnel barrier layer, (Co₇₀Fe₃₀)₈₀B₂₀ (3 nm) is used as themagnetic recording layer, AlOx (0.7 nm) is used as the dielectric whichdivides the non-magnetic metal layer and the magnetic layer, Au (5 nm)is used as the non-magnetic metal layer, a Co₇₀Fe₃₀ layer (3 nm) is usedas the magnetic layer in the second magnetization pinned layer dividedby the dielectric, Co₇₀Fe₃₀ (4 nm)/Ru (0.85 nm)/CO₇₀Fe₃₀ (3 nm)/Ru (0.85nm)/Co₇₀Fe₃₀ (3 nm) is used as the remaining second magnetization pinnedlayer, and PtMn (14 nm) is used as the antiferromagnetic layer in orderfrom the bottom.

AlOx (0.7 nm) used as the dielectric which divides the non-magneticmetal layer is fabricated by using a patterned self-aligned process. Itsfabrication method is nearly the same as that in the second example.

Furthermore, a fifth comparative sample and a sixth comparative sampleare fabricated. The fifth comparative sample and the sixth comparativesample are samples obtained by forming the non-magnetic metal layer inthe fifth sample and the sixth sample as a continuous film withoutconducting patterning.

Both the third example and the comparative example have a junction sizeof 0.1×0.18 μm². After the fabrication, a magnetic field is applied tothe long axis direction of the magnetic layer at 350° C. in order toconduct annealing in the magnetic field.

A 200 nm pulse current is applied to the fifth sample, the fifthcomparative sample, the sixth sample, and the sixth comparative sample,and a current (mA) at which the spin is inverted is checked. As aresult, the spin is inverted at 0.065 mA in the fifth sample, at 0.23 mAin the fifth comparative sample, at 0.062 mA in the sixth sample, and at0.27 mA in the sixth comparative sample. Therefore, it is appreciatedthat the structure of the present example is suitable as a largecapacity memory and spin injection writing can be conducted at a lowcurrent. As a result of repetitive measurements, spin injection writingup to the number of times of writing of 10⁶ can be ascertained, and thereliability of the present structure can be ascertained.

FOURTH EXAMPLE

As a fourth example of the present invention, the magnetoresistiveeffect element 1A according to the first modification of the secondembodiment shown in FIG. 10 and the magnetoresistive effect elementaccording to the first modification of the fourth embodiment shown inFIG. 19 are fabricated respectively as a seventh sample and an eighthsample. As a comparative example, a magnetoresistive effect elementhaving a structure shown in FIG. 27 is fabricated. In addition, in themagnetoresistive effect element having the structure shown in FIG. 28,the first magnetization pinned layer 6 is formed as a three-layerstructure represented as a magnetic layer/a non-magnetic layer/amagnetic layer and the second magnetization pinned layer 15 is formed asa five-layer structure represented as a magnetic layer/a non-magneticlayer/a magnetic layer/a non-magnetic layer/a magnetic layer. In thisway, an eighth comparative sample is fabricated. These samples arecompared in terms of the spin inversion current. Sections of thefabricated magnetoresistive effect elements shown in FIG. 10 and FIG. 19are observed using a TEM. As a result, it is found that the dielectricis not formed as far as 1 nm from the top of the magnetic recordinglayer as shown in FIG. 13 and FIG. 22 and the non-magnetic layer is notdivided completely by the dielectric, but a part of the non-magneticlayer is divided (on the second magnetization pinned layer side).

As to the structure of the magnetoresistive effect element according tothe fourth example, its manufacturing method is the same as that in thesecond example.

As the seventh sample, a TMR film, i.e., a laminated film including anunderlying layer/an antiferromagnetic layer/a magnetic layer/anon-magnetic layer/a magnetic layer/a tunnel barrier layer/a magneticlayer/a non-magnetic metal layer divided by a dielectric/a magneticlayer/a non-magnetic layer/a magnetic layer/an antiferromagnetic layer/acap layer formed of Ru (not illustrated)/a metal hard mask is formed ona lower electrode (not illustrated) provided on a substrate, as shown inFIG. 10.

As the eighth sample, a TMR film, i.e., a laminated film including anunderlying layer/an antiferromagnetic layer/a magnetic layer/anon-magnetic layer/a magnetic layer/a tunnel barrier layer/a magneticlayer/a non-magnetic metal layer divided by a dielectric/a magneticlayer/a non-magnetic layer/a magnetic layer/a non-magnetic layer/amagnetic layer/an antiferromagnetic layer/a cap layer formed of Ru (notillustrated)/a metal hard mask is formed on a lower electrode (notillustrated) as shown in FIG. 19.

In the present example, all of lower wiring is formed of Ta/Cu/Ta andall of the underlying layer is formed of Ru. In the TMR film of theseventh sample, PtMn (14 nm) is used as the antiferromagnetic layer,Co₇₀Fe₃₀ (4 nm)/Ru (0.85 nm)/(Co₇₀Fe₃₀)₈₀B₂₀ (4 nm) is used as the firstmagnetization pinned layer, MgO (1.0 nm) is used as the tunnel barrierlayer, (Co₇₀Fe₃₀)₈₀B₂₀ (3 nm) is used as the magnetic recording layer,an Ru layer having a thickness of approximately 1 nm is used, AlOx isused as the dielectric, an Ru layer (4 nm) divided by the dielectric isused, Co₇₀Fe₃₀ (4 nm)/Ru (0.85 nm)/Co₇₀Fe₃₀ (3 nm) is used as the secondmagnetization pinned layer, and PtMn (14 nm) is used as theantiferromagnetic layer in order from the bottom. In the seventh sample,the Ru layer having the thickness of approximately 1 nm and the Ru layer(4 nm) serving as the non-magnetic metal layer divided by the dielectricconstitute the non-magnetic metal layer.

In the TMR film of the eighth sample, PtMn (14 nm) is used as theantiferromagnetic layer, Co₇₀Fe₃₀ (3 nm)/Ru (0.85 nm)/(Co₇₀Fe₃₀)₈₀B₂₀ (4nm) is used as the first magnetization pinned layer, MgO (1.0 nm) isused as the tunnel barrier layer, (Co₇₀Fe₃₀)₈₀B₂₀ (3 nm) is used as themagnetic recording layer, a thin Au layer having a thickness ofapproximately 1 nm is used, AlOx (0.7 nm) is used as the dielectric, anAu layer (4 nm) divided by the dielectric is used, Co₇₀Fe₃₀ (4 nm)/Ru(0.85 nm)/Co₇₀Fe₃₀ (3 nm)/Ru (0.85 nm)/Co₇₀Fe₃₀ (3 nm) is used as thesecond magnetization pinned layer, and PtMn (14 nm) is used as theantiferromagnetic layer in order from the bottom. In the eighth sample,the thin Au layer having the thickness of approximately 1 nm and the Aulayer (4 nm) divided by the dielectric constitute the non-magnetic metallayer.

AlOx (0.7 nm) used as the dielectric layer which divides thenon-magnetic metal layer is fabricated by using a patterned self-alignedprocess. Its fabrication method is nearly the same as that in the secondexample.

Both the fourth example and the comparative example have a junction sizeof 0.1×0.18 μm². After the fabrication, a magnetic field is applied tothe long axis direction of the magnetic layer at 350° C. in order toconduct annealing in the magnetic field.

A 200 nm pulse current is applied to the seventh sample, the seventhcomparative sample, the eighth sample, and the eighth comparativesample, and a current (mA) at which the spin is inverted is checked. Asa result, the spin is inverted at 0.063 mA in the seventh sample, at0.22 mA in the seventh comparative sample, at 0.06 mA in the eighthsample, and at 0.26 mA in the eighth comparative sample. Therefore, itis appreciated that the structure of the present example is suitable asa large capacity memory and spin injection writing can be conducted at alow current. As a result of repetitive measurements, spin injectionwriting up to the number of times of writing of 10⁶ can be ascertained,and the reliability of the present structure can be ascertained. On thebasis of the present example, it is made clear that the current can bereduced without a problem even if a non-magnetic metal layer having athickness of approximately 1 nm is not divided.

According to the embodiments of the present invention, it is possible toprovide a highly reliable magnetoresistive effect element that operateswith low power consumption and low current writing and without elementdestruction as heretofore described.

Heretofore, embodiments of the present invention have been describedwith reference to concrete examples. However, the present invention isnot limited to these concrete examples. For example, concrete materialsof the ferromagnetic substance layer, insulation film, antiferromagneticsubstance layer, non-magnetic metal layer and electrode included in themagnetoresistive effect element, and the layer thickness, shape anddimension that can be suitably selected by those skilled in the art toexecute the present invention and obtain similar effects are alsoincorporated in the scope of the present invention.

In the same way, the structure, material quality, shape and dimension ofelements included in the magnetic memory of the present invention thatcan be suitably selected by those skilled in the art to execute thepresent invention in the same way and obtain similar effects are alsoincorporated in the scope of the present invention.

All magnetic memories that can be suitably changed in design andexecuted by those skilled in the art on the basis of the magneticmemories described above as embodiments of the present invention alsobelong to the scope of the present invention in the same way.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcepts as defined by the appended claims and their equivalents.

1. A magnetoresistive effect element comprising: a first magnetizationpinned layer which comprises at least one magnetic layer and in which amagnetization direction is pinned; a magnetization free layer in which amagnetization direction is changeable; a tunnel barrier layer providedbetween the first magnetization pinned layer and the magnetization freelayer; a non-magnetic metal layer provided on a first region in anopposite surface of the magnetization free layer from the tunnel barrierlayer; a dielectric layer provided on a second region other than thefirst region in the opposite surface of the magnetization free layerfrom the tunnel barrier layer; and a second magnetization pinned layerwhich comprises at least one magnetic layer and in which a magnetizationdirection is pinned, the second magnetization pinned layer beingprovided so as to cover opposite surfaces respectively of thenon-magnetic metal layer and the dielectric layer from the magnetizationfree layer.
 2. The magnetoresistive effect element according to claim 1,wherein an interface between the dielectric layer and the secondmagnetization pinned layer and an interface between the non-magneticmetal layer and the second magnetization pinned layer are substantiallycoplanar.
 3. The magnetoresistive effect element according to claim 1,wherein an interface between the dielectric layer and the secondmagnetization pinned layer is located farther from an interface betweenthe tunnel barrier layer and the magnetization free layer than aninterface between the non-magnetic metal layer and the secondmagnetization pinned layer.
 4. The magnetoresistive effect elementaccording to claim 1, wherein the second magnetization pinned layer hasa three-layer structure in which a first magnetic layer, a firstnon-magnetic layer, and a second magnetic layer are stacked in orderfrom a side of the non-magnetic metal layer, or a five-layer structurein which a first magnetic layer, a first non-magnetic layer, a secondmagnetic layer, a second non-magnetic layer, and a third magnetic layerare stacked in order from the side of the non-magnetic metal layer, andan interface between the dielectric layer and the second magnetizationpinned layer exists in the first magnetic layer.
 5. The magnetoresistiveeffect element according to claim 1, wherein a magnetization directionof a magnetic layer included in the first magnetization pinned layer andlocated nearest the magnetization free layer is substantially parallelto a magnetization direction of a magnetic layer included in the secondmagnetization pinned layer and located nearest the magnetization freelayer, and the non-magnetic metal layer comprises Ru, Ir, Os or an alloyof them.
 6. The magnetoresistive effect element according to claim 1,wherein a magnetization direction of a magnetic layer included in thefirst magnetization pinned layer and located nearest the magnetizationfree layer is substantially antiparallel to a magnetization direction ofa magnetic layer included in the second magnetization pinned layer andlocated nearest the magnetization free layer, and the non-magnetic metallayer comprises Cu, Ag, Au, Rh, Ir, or an alloy of them.
 7. Themagnetoresistive effect element according to claim 1, wherein thedielectric layer and the tunnel barrier layer comprises Al₂O₃, SiO₂,MgO, AlN, SiON, or AlON.
 8. The magnetoresistive effect elementaccording to claim 1, wherein at least one of the first and secondmagnetization pinned layers has a three-layer structure comprising amagnetic layer/a non-magnetic layer/a magnetic layer, or a five-layerstructure comprising a magnetic layer/a non-magnetic layer/a magneticlayer/a non-magnetic layer/a magnetic layer.
 9. A magnetoresistiveeffect element comprising: a first magnetization pinned layer whichcomprises at least one magnetic layer and in which a magnetizationdirection is pinned; a magnetization free layer in which a magnetizationdirection is changeable; a tunnel barrier layer provided between thefirst magnetization pinned layer and the magnetization free layer; anon-magnetic metal layer provided on a first region in an oppositesurface of the magnetization free layer from the tunnel barrier layer; adielectric layer provided on a second region other than the first regionin the opposite surface of the magnetization free layer from the tunnelbarrier layer; and a second magnetization pinned layer which comprisesat least one magnetic layer and in which a magnetization direction ispinned, the second magnetization pinned layer being provided on anopposite surface of the non-magnetic metal layer from the magnetizationfree layer.
 10. The magnetoresistive effect element according to claim9, wherein an interface between the dielectric layer and themagnetization free layer and an interface between the non-magnetic metallayer and the magnetization free layer are substantially coplanar. 11.The magnetoresistive effect element according to claim 9, wherein aninterface between the dielectric layer and the magnetization free layeris located nearer an interface between the tunnel barrier layer and themagnetization free layer than an interface between the non-magneticmetal layer and the magnetization free layer.
 12. The magnetoresistiveeffect element according to claim 9, wherein a magnetization directionof a magnetic layer included in the first magnetization pinned layer andlocated nearest the magnetization free layer is substantially parallelto a magnetization direction of a magnetic layer included in the secondmagnetization pinned layer and located nearest the magnetization freelayer, and the non-magnetic metal layer comprises Ru, Ir, Os or an alloyof them.
 13. The magnetoresistive effect element according to claim 9,wherein a magnetization direction of a magnetic layer included in thefirst magnetization pinned layer and located nearest the magnetizationfree layer is substantially antiparallel to a magnetization direction ofa magnetic layer included in the second magnetization pinned layer andlocated nearest the magnetization free layer, and the non-magnetic metallayer comprises Cu, Ag, Au, Rh, Ir, or an alloy of them.
 14. Themagnetoresistive effect element according to claim 9, wherein thedielectric layer and the tunnel barrier layer comprises Al₂O₃, SiO₂,MgO, AlN, SiON, or AlON.
 15. The magnetoresistive effect elementaccording to claim 9, wherein at least one of the first and secondmagnetization pinned layers has a three-layer structure comprising amagnetic layer/a non-magnetic layer/a magnetic layer, or a five-layerstructure comprising a magnetic layer/a non-magnetic layer/a magneticlayer/a non-magnetic layer/a magnetic layer.
 16. A magnetoresistiveeffect element comprising: a first magnetization pinned layer whichcomprises at least one magnetic layer and in which a magnetizationdirection is pinned; a magnetization free layer in which a magnetizationdirection is changeable; a tunnel barrier layer provided between thefirst magnetization pinned layer and the magnetization free layer; anon-magnetic metal layer provided on an opposite surface of themagnetization free layer from the tunnel barrier layer; a dielectriclayer provided on a first region in an opposite surface of thenon-magnetic metal layer from the magnetization free layer; and a secondmagnetization pinned layer which comprises at least one magnetic layerand in which a magnetization direction is pinned, the secondmagnetization pinned layer being provided so as to cover a second regionother than the first region in the opposite surface of the non-magneticmetal layer from the magnetization free layer and an opposite surface ofthe dielectric layer from the non-magnetic metal layer.
 17. Themagnetoresistive effect element according to claim 16, wherein aninterface between the dielectric layer and the second magnetizationpinned layer and an interface between the non-magnetic metal layer andthe second magnetization pinned layer are substantially coplanar. 18.The magnetoresistive effect element according to claim 16, wherein aninterface between the dielectric layer and the second magnetizationpinned layer is located farther from an interface between the tunnelbarrier layer and the magnetization free layer than an interface betweenthe non-magnetic metal layer and the second magnetization pinned layer.19. The magnetoresistive effect element according to claim 16, whereinthe second magnetization pinned layer has a three-layer structure inwhich a first magnetic layer, a first non-magnetic layer, and a secondmagnetic layer are stacked in order from a side of the non-magneticmetal layer, or a five-layer structure in which a first magnetic layer,a first non-magnetic layer, a second magnetic layer, a secondnon-magnetic layer, and a third magnetic layer are stacked in order fromthe side of the non-magnetic metal layer, and an interface between thedielectric layer and the second magnetization pinned layer exists in thefirst magnetic layer.
 20. The magnetoresistive effect element accordingto claim 16, wherein a magnetization direction of a magnetic layerincluded in the first magnetization pinned layer and located nearest themagnetization free layer is substantially parallel to a magnetizationdirection of a magnetic layer included in the second magnetizationpinned layer and located nearest the magnetization free layer, and thenon-magnetic metal layer comprises Ru, Ir, Os or an alloy of them. 21.The magnetoresistive effect element according to claim 16, wherein amagnetization direction of a magnetic layer included in the firstmagnetization pinned layer and located nearest the magnetization freelayer is substantially antiparallel to a magnetization direction of amagnetic layer included in the second magnetization pinned layer andlocated nearest the magnetization free layer, and the non-magnetic metallayer comprises Cu, Ag, Au, Rh, Ir, or an alloy of them.
 22. Themagnetoresistive effect element according to claim 16, wherein thedielectric layer and the tunnel barrier layer comprises Al₂O₃, SiO₂,MgO, AlN, SiON, or AlON.
 23. The magnetoresistive effect elementaccording to claim 16, wherein at least one of the first and secondmagnetization pinned layers has a three-layer structure comprising amagnetic layer/a non-magnetic layer/a magnetic layer, or a five-layerstructure comprising a magnetic layer/a non-magnetic layer/a magneticlayer/a non-magnetic layer/a magnetic layer.
 24. A magnetoresistiveeffect element comprising: a first magnetization pinned layer whichcomprises at least one magnetic layer and in which a magnetizationdirection is pinned; a magnetization free layer in which a magnetizationdirection is changeable; a tunnel barrier layer provided between thefirst magnetization pinned layer and the magnetization free layer; anon-magnetic metal layer provided on an opposite surface of themagnetization free layer from the tunnel barrier layer; a dielectriclayer provided on a first region in an opposite surface of thenon-magnetic metal layer from the magnetization free layer; and a secondmagnetization pinned layer which comprises at least one magnetic layerand in which a magnetization direction is pinned, the secondmagnetization pinned layer being provided on a second region other thanthe first region in the opposite surface of the non-magnetic metal layerfrom the magnetization free layer.
 25. The magnetoresistive effectelement according to claim 24, wherein an interface between thenon-magnetic metal layer and the dielectric layer is located nearer aninterface between the tunnel barrier layer and the magnetization freelayer than an interface between the non-magnetic metal layer and thesecond magnetization pinned layer.
 26. The magnetoresistive effectelement according to claim 24, wherein a magnetization direction of amagnetic layer included in the first magnetization pinned layer andlocated nearest the magnetization free layer is substantially parallelto a magnetization direction of a magnetic layer included in the secondmagnetization pinned layer and located nearest the magnetization freelayer, and the non-magnetic metal layer comprises Ru, Ir, Os or an alloyof them.
 27. The magnetoresistive effect element according to claim 24,wherein a magnetization direction of a magnetic layer included in thefirst magnetization pinned layer and located nearest the magnetizationfree layer is substantially antiparallel to a magnetization direction ofa magnetic layer included in the second magnetization pinned layer andlocated nearest the magnetization free layer, and the non-magnetic metallayer comprises Cu, Ag, Au, Rh, Ir, or an alloy of them.
 28. Themagnetoresistive effect element according to claim 24, wherein thedielectric layer and the tunnel barrier layer comprises Al₂O₃, SiO₂,MgO, AlN, SiON, or AlON.
 29. The magnetoresistive effect elementaccording to claim 24, wherein at least one of the first and secondmagnetization pinned layers has a three-layer structure comprising amagnetic layer/a non-magnetic layer/a magnetic layer, or a five-layerstructure comprising a magnetic layer/a non-magnetic layer/a magneticlayer/a non-magnetic layer/a magnetic layer.
 30. A magnetoresistiveeffect element comprising: a first magnetization pinned layer whichcomprises at least one magnetic layer and in which a magnetizationdirection is pinned; a magnetization free layer in which a magnetizationdirection is changeable; a tunnel barrier layer provided between thefirst magnetization pinned layer and the magnetization free layer; adielectric layer provided on a first region in an opposite surface ofthe magnetization free layer from the tunnel barrier layer; anon-magnetic metal layer provided on a second region other than thefirst region in the opposite surface of the magnetization free layerfrom the tunnel barrier layer so as to cover an opposite surface of thedielectric layer from the magnetization free layer; and a secondmagnetization pinned layer which comprises at least one magnetic layerand in which a magnetization direction is pinned, the secondmagnetization pinned layer being provided on an opposite surface of thenon-magnetic metal layer from the magnetization free layer.
 31. Themagnetoresistive effect element according to claim 30, wherein aninterface between the dielectric layer and the magnetization free layerand an interface between the non-magnetic metal layer and themagnetization free layer are substantially coplanar.
 32. Themagnetoresistive effect element according to claim 30, wherein aninterface between the dielectric layer and the magnetization free layeris located nearer an interface between the tunnel barrier layer and themagnetization free layer than an interface between the non-magneticmetal layer and the magnetization free layer.
 33. The magnetoresistiveeffect element according to claim 30, wherein an interface between thenon-magnetic metal layer and the dielectric layer is located fartherfrom an interface between the tunnel barrier layer and the magnetizationfree layer than an interface between the non-magnetic metal layer andthe magnetization free layer.
 34. The magnetoresistive effect elementaccording to claim 30, wherein a magnetization direction of a magneticlayer included in the first magnetization pinned layer and locatednearest the magnetization free layer is substantially parallel to amagnetization direction of a magnetic layer included in the secondmagnetization pinned layer and located nearest the magnetization freelayer, and the non-magnetic metal layer comprises Ru, Ir, Os or an alloyof them.
 35. The magnetoresistive effect element according to claim 30,wherein a magnetization direction of a magnetic layer included in thefirst magnetization pinned layer and located nearest the magnetizationfree layer is substantially antiparallel to a magnetization direction ofa magnetic layer included in the second magnetization pinned layer andlocated nearest the magnetization free layer, and the non-magnetic metallayer comprises Cu, Ag, Au, Rh, Ir, or an alloy of them.
 36. Themagnetoresistive effect element according to claim 30, wherein thedielectric layer and the tunnel barrier layer comprises Al₂O₃, SiO₂,MgO, AlN, SiON, or AlON.
 37. The magnetoresistive effect elementaccording to claim 30, wherein at least one of the first and secondmagnetization pinned layers has a three-layer structure comprising amagnetic layer/a non-magnetic layer/a magnetic layer, or a five-layerstructure comprising a magnetic layer/a non-magnetic layer/a magneticlayer/a non-magnetic layer/a magnetic layer.
 38. A magnetoresistiveeffect element comprising: a first magnetization pinned layer whichcomprises at least one magnetic layer and in which a magnetizationdirection is pinned; a magnetization free layer in which a magnetizationdirection is changeable; a tunnel barrier layer provided between thefirst magnetization pinned layer and the magnetization free layer; anon-magnetic metal layer provided on an opposite surface of themagnetization free layer from the tunnel barrier layer; a secondmagnetization pinned layer which comprises at least one magnetic layerand in which a magnetization direction is pinned, the secondmagnetization pinned layer being provided on an opposite surface of thenon-magnetic metal layer from the magnetization free layer; and adielectric layer which passes through the magnetization free layer andat least a part of the non-magnetic metal layer and which does not passthrough the second magnetization pinned layer.
 39. The magnetoresistiveeffect element according to claim 38, wherein a magnetization directionof a magnetic layer included in the first magnetization pinned layer andlocated nearest the magnetization free layer is substantially parallelto a magnetization direction of a magnetic layer included in the secondmagnetization pinned layer and located nearest the magnetization freelayer, and the non-magnetic metal layer comprises Ru, Ir, Os or an alloyof them.
 40. The magnetoresistive effect element according to claim 38,wherein a magnetization direction of a magnetic layer included in thefirst magnetization pinned layer and located nearest the magnetizationfree layer is substantially antiparallel to a magnetization direction ofa magnetic layer included in the second magnetization pinned layer andlocated nearest the magnetization free layer, and the non-magnetic metallayer comprises Cu, Ag, Au, Rh, Ir, or an alloy of them.
 41. Themagnetoresistive effect element according to claim 38, wherein thedielectric layer and the tunnel barrier layer comprises Al₂O₃, SiO₂,MgO, AlN, SiON, or AlON.
 42. The magnetoresistive effect elementaccording to claim 38, wherein at least one of the first and secondmagnetization pinned layers has a three-layer structure comprising amagnetic layer/a non-magnetic layer/a magnetic layer, or a five-layerstructure comprising a magnetic layer/a non-magnetic layer/a magneticlayer/a non-magnetic layer/a magnetic layer.
 43. A magnetic memorycomprising: a memory cell comprising a magnetoresistive effect elementaccording to claim 1; a first wiring electrically connected to one endof the magnetoresistive effect element; and a second wiring electricallyconnected to the other end of the magnetoresistive effect element.
 44. Amagnetic memory comprising: a memory cell comprising a magnetoresistiveeffect element according to claim 9; a first wiring electricallyconnected to one end of the magnetoresistive effect element; and asecond wiring electrically connected to the other end of themagnetoresistive effect element.
 45. A magnetic memory comprising: amemory cell comprising a magnetoresistive effect element according toclaim 16; a first wiring electrically connected to one end of themagnetoresistive effect element; and a second wiring electricallyconnected to the other end of the magnetoresistive effect element.
 46. Amagnetic memory comprising: a memory cell comprising a magnetoresistiveeffect element according to claim 24; a first wiring electricallyconnected to one end of the magnetoresistive effect element; and asecond wiring electrically connected to the other end of themagnetoresistive effect element.
 47. A magnetic memory comprising: amemory cell comprising a magnetoresistive effect element according toclaim 30; a first wiring electrically connected to one end of themagnetoresistive effect element; and a second wiring electricallyconnected to the other end of the magnetoresistive effect element.
 48. Amagnetic memory comprising: a memory cell comprising a magnetoresistiveeffect element according to claim 38; a first wiring electricallyconnected to one end of the magnetoresistive effect element; and asecond wiring electrically connected to the other end of themagnetoresistive effect element.